The war drew in all the world's economic great powers, assembled in two opposing alliances: the Allies (based on the Triple Entente of the British Empire, France and the Russian Empire) versus the Central Powers of Germany and Austria-Hungary. Although Italy was a member of the Triple Alliance alongside Germany and Austria-Hungary, it did not join the Central Powers, as Austria-Hungary had taken the offensive, against the terms of the alliance. These alliances were reorganised and expanded as more nations entered the war: Italy and Japan joined the Allies, while the Ottoman Empire, Bulgaria, and the United States joined the Central Powers.
The trigger for the war was the assassination of Archduke Franz Ferdinand of Austria, heir to the throne of Austria-Hungary, by Yugoslav nationalist Gavrilo Princip in Sarajevo on 28 June 1914. This set off a diplomatic crisis when Austria-Hungary delivered an ultimatum to the Kingdom of Serbia, and entangled international alliances formed over the previous decades were invoked. Within weeks, the major powers were at war and the conflict soon spread around the world. On 28 July, the Austro-Hungarians declared war on Serbia. As Russia mobilized in support of Serbia, Germany invaded neutral Belgium and Luxembourg before moving towards France, leading the United Kingdom to declare war on Germany. After the German march on Paris was halted, what became known as the Western Front settled into a battle of attrition, with a trench line that changed little until 1917.
On the Eastern Front, the Russian army was successful against the Austro-Hungarians, but the Germans stopped its invasion of East Prussia. In November 1914, the Ottoman Empire joined the Central Powers, opening fronts in the Caucasus, Mesopotamia and the Sinai. In 1915, Italy joined the Allies and Bulgaria joined the Central Power as did the United States; Romania joined the Allies in 1916. The Russian government collapsed in March 1917, and a revolution in November brought the Russians to terms with the Central Powers via the Treaty of Brest Litovsk, which was a massive German victory. After a stunning German offensive along the Western Front in the spring of 1918
From the time of its start until the approach of World War II, the First World War was called simply the World War or the Great War and thereafter the First World War or World War I. At the time, it was also sometimes called "the war to end war" or "the war to end all wars" due to its then-unparalleled scale and devastation. In Canada, Maclean's magazine in October 1914 wrote, "Some wars name themselves. This is the Great War." During the interwar period (1918–1939), the war was most often called the World War and the Great War in English-speaking countries. The term "First World War" was first used in September 1914 by the German biologist and philosopher Ernst Haeckel, who claimed that "there is no doubt that the course and character of the feared 'European War' ... will become the first world war in the full sense of the word," citing a wire service report in The Indianapolis Star on 20 September 1914. After the onset of the Second World War in 1939, the terms World War I or the First World War became standard, with British and Canadian historians favoring the First World War, and Americans World War I.
Political and Military Alliances
During the 19th century, the major European powers went to great lengths to maintain a balance of power throughout Europe, resulting in the existence of a complex network of political and military alliances throughout the continent by 1900. These began in 1815, with the Holy Alliance between Prussia, Russia, and Austria. When Germany was united in 1871, Prussia became part of the new German nation. Soon after, in October 1873, German Chancellor Otto von Bismarck negotiated the League of the Three Emperors (German: Dreikaiserbund) between the monarchs of Austria-Hungary, Russia and Germany. This agreement failed because Austria-Hungary and Russia could not agree over Balkan policy, leaving Germany and Austria-Hungary in an alliance formed in 1879, called the Dual Alliance. This was seen as a method of countering Russian influence in the Balkans as the Ottoman Empire continued to weaken. This alliance expanded, in 1882, to include Italy in what became the Triple Alliance.
Bismarck had especially worked to hold Russia at Germany's side in an effort to avoid a two-front war with France and Russia. When Wilhelm II ascended to the throne as German Emperor (Kaiser), Bismarck was compelled to retire and his system of alliances was gradually de-emphasized. For example, the Kaiser refused, in 1890, to renew the Reinsurance Treaty with Russia. Two years later, the Franco-Russian Alliance was signed to counteract the force of the Triple Alliance. In 1904, Britain signed a series of agreements with France, the Entente Cordiale, and in 1907, Britain and Russia signed the Anglo-Russian Convention. While these agreements did not formally ally Britain with France or Russia, they made British entry into any future conflict involving France or Russia a possibility, and the system of interlocking bilateral agreements became known as the Triple Entente.
German industrial and economic power had grown greatly after unification and the foundation of the Empire in 1871 following the Franco-Prussian War. From the mid-1890s on, the government of Wilhelm II used this base to devote significant economic resources for building up the Kaiserliche Marine (Imperial German Navy), established by Admiral Alfred von Tirpitz, in rivalry with the British Royal Navy for world naval supremacy. As a result, each nation strove to out-build the other in capital ships. With the launch of HMS Dreadnought in 1906, the British Empire expanded on its significant advantage over its German rival. The arms race between Britain and Germany eventually extended to the rest of Europe, with all the major powers devoting their industrial base to producing the equipment and weapons necessary for a pan-European conflict. Between 1908 and 1913, the military spending of the European powers increased by 50%.
The United States was yet another nation which drastically expanded its military force in the intervening and pre war years. from 1904-1914 the United States specifically expanded its naval forces to be able to challenge the combined mights of at least two other great powers in this case matching its fleet size to be able to beat the French and the Japanese. This brought great tension between the French, Japanese, and the United States both of which decried the American Buildup. This however eventually grew into a naval force that was on par with with the German Empire and according to the British Admiralty "A grave threat to the British Rule of the Seas". By the outset of World War 1 the US had 14 dreadnoughts, 5 battlecruisers, 23 pre-dreadnought battleships, 15 armored cruisers, 30 protected cruisers, 5 light cruisers, and nearly 70 destroyers as well as a small amount of submarines and other craft. The US was also heavily invested in expanding its destroyer and light cruiser force intending on rivaling the british light fleet capabilities and relying on its superior industrial capacity in any war to ramp up production and challenge any other attempts to fight the US navy.
Conflicts in the Balkans
Austria-Hungary precipitated the Bosnian crisis of 1908–1909 by officially annexing the former Ottoman territory of Bosnia and Herzegovina, which it had occupied since 1878. This angered the Kingdom of Serbia and its patron, the Pan-Slavic and Orthodox Russian Empire. Russian political manoeuvring in the region destabilised peace accords, which were already fracturing in the Balkans which came to be known as the "powder keg of Europe". In 1912 and 1913, the First Balkan War was fought between the Balkan League and the fracturing Ottoman Empire. The resulting Treaty of London further shrank the Ottoman Empire, creating an independent Albanian state while enlarging the territorial holdings of Bulgaria, Serbia, Montenegro, and Greece. When Bulgaria attacked Serbia and Greece on 16 June 1913, it lost most of Macedonia to Serbia and Greece and Southern Dobruja to Romania in the 33-day Second Balkan War, further destabilising the region.
On 28 June 1914, Austrian Archduke Franz Ferdinand visited the Bosnian capital, Sarajevo. A group of six assassins (Cvjetko Popović, Gavrilo Princip, Muhamed Mehmedbašić, Nedeljko Čabrinović, Trifko Grabež, Vaso Čubrilović) from the nationalist group Mlada Bosna, supplied by the Black Hand, had gathered on the street where the Archduke's motorcade would pass, with the intention of assassinating the Archduke. Čabrinović threw a grenade at the car, but missed. Some nearby were injured by the blast, but Franz Ferdinand's convoy carried on. The other assassins failed to act as the cars drove past them.
About an hour later, when Franz Ferdinand was returning from a visit at the Sarajevo Hospital with those wounded in the assassination attempt, the convoy took a wrong turn into a street where, by coincidence, Princip stood. With a pistol, Princip shot and killed Franz Ferdinand and his wife Sophie. The reaction among the people in Austria was mild, almost indifferent. As historian Zbyněk Zeman later wrote, "the event almost failed to make any impression whatsoever. On Sunday and Monday (28 and 29 June), the crowds in Vienna listened to music and drank wine, as if nothing had happened."
Crowds on the streets in the aftermath of the anti-Serb riots in Sarajevo, 29 June 1914 The Austro-Hungarian authorities encouraged the anti-Serb riots in Sarajevo, in which Croats and Bosniaks killed two ethnic Serbs and damaged numerous Serb-owned buildings. Violent actions against ethnic Serbs were also organized outside Sarajevo, in large Austro-Hungarian cities in modern-day Bosnia and Herzegovina, Croatia and Slovenia. Austro-Hungarian authorities in Bosnia and Herzegovina imprisoned and extradited approximately 5,500 prominent Serbs, 700 to 2,200 of whom died in prison. A further 460 Serbs were sentenced to death and a predominantly Bosniak special militia known as the Schutzkorps was established and carried out the persecution of Serbs.
The assassination led to a month of diplomatic manoeuvring between Austria-Hungary, Germany, Russia, France, and Britain called the July Crisis. Believing correctly that Serbian officials (especially the officers of the Black Hand) were involved in the plot to murder the Archduke, and wanting to finally end Serbian interference in Bosnia, Austria-Hungary delivered to Serbia on 23 July the July Ultimatum, a series of ten demands that were made intentionally unacceptable, in an effort to provoke a war with Serbia. The next day, after the Council of Ministers of Russia was held under the chairmanship of the Tsar at Krasnoe Selo, Russia ordered general mobilization for Odessa, Kiev, Kazan and Moscow military districts and fleets of the Baltic and the Black Sea. They also asked for other regions to accelerate preparations for general mobilization. Serbia decreed general mobilization on the 25th and that night, declared that they accepted all the terms of the ultimatum, except article six, which demanded that Austrian delegates be allowed in Serbia for the purpose of participation in the investigation into the assassination. Following this, Austria broke off diplomatic relations with Serbia, and the next day ordered a partial mobilization. Finally, on 28 July 1914, Austria-Hungary declared war on Serbia.
On 29 July, Russia, in support of its Serb protégé, unilaterally declared – outside of the conciliation procedure provided by the Franco-Russian military agreements – partial mobilization against Austria-Hungary. German Chancellor Bethmann-Hollweg was then allowed until the 31st for an appropriate response. On the 30th, Russia ordered general mobilization against Germany. In response, the following day, Germany declared a "state of danger of war." This also led to the general mobilization in Austria-Hungary on 4 August. Kaiser Wilhelm II asked his cousin, Tsar Nicolas II, to suspend the Russian general mobilization. When he refused, Germany issued an ultimatum demanding the arrest of its mobilization and commitment not to support Serbia. Another was sent to France, asking her not to support Russia if it were to come to the defence of Serbia. On 1 August, after the Russian response, Germany mobilized and declared war on Russia.
The German government issued demands to France that it remain neutral as they had to decide which deployment plan to implement, it being difficult if not impossible to change the deployment whilst it was underway. The modified German Schlieffen Plan, Aufmarsch II West, would deploy 80% of the army in the west, and Aufmarsch I Ost and Aufmarsch II Ost would deploy 60% in the west and 40% in the east as this was the maximum that the East Prussian railway infrastructure could carry. The French did not respond but sent a mixed message by ordering their troops to withdraw 10 km (6 mi) from the border to avoid any incidents, but at the same time ordered the mobilisation of her reserves. Germany responded by mobilising its own reserves and implementing Aufmarsch II West. Germany attacked Luxembourg on 2 August and on 3 August declared war on France. On 4 August, after Belgium refused to permit German troops to cross its borders into France, Germany declared war on Belgium as well. Britain declared war on Germany at 19:00 UTC on 4 August 1914 (effective from 11 pm), following an "unsatisfactory reply" to the British ultimatum that Belgium must be kept neutral.
Progress of the War
Central Power Confusion
The strategy of the Central Powers suffered from miscommunication. Germany had promised to support Austria-Hungary's invasion of Serbia, but interpretations of what this meant differed. Previously tested deployment plans had been replaced early in 1914, but those had never been tested in exercises. Austro-Hungarian leaders believed Germany would cover its northern flank against Russia. Germany, however, envisioned Austria-Hungary directing most of its troops against Russia, while Germany dealt with France. This confusion forced the Austro-Hungarian Army to divide its forces between the Russian and Serbian fronts.
Austria invaded and fought the Serbian army at the Battle of Cer and Battle of Kolubara beginning on 12 August. Over the next two weeks, Austrian attacks were thrown back with heavy losses, which marked the first major Allied victories of the war and dashed Austro-Hungarian hopes of a swift victory. As a result, Austria had to keep sizable forces on the Serbian front, weakening its efforts against Russia. Serbia's defeat of the Austro-Hungarian invasion of 1914 counts among the major upset victories of the twentieth century.
German Invasion of Belgium and France
At the outbreak of World War I, 80% of the German army was deployed as seven field armies in the west according to the plan Aufmarsch II West. However, they were then assigned to execute the retired deployment plan Aufmarsch I West, also known as the Schlieffen Plan. This would march German armies through northern Belgium and into France, in an attempt to encircle the French army and then breach the 'second defensive area' of the fortresses of Verdun and Paris and the Marne river.
Aufmarsch I West was one of four deployment plans available to the German General Staff in 1914. Each plan favoured certain operations, but did not specify exactly how those operations were to be carried out, leaving the commanding officers to carry those out at their own initiative and with minimal oversight.[clarification needed] Aufmarsch I West, designed for a one-front war with France, had been retired once it became clear it was irrelevant to the wars Germany could expect to face; both Russia and Britain were expected to help France, and there was no possibility of Italian nor Austro-Hungarian troops being available for operations against France. But despite its unsuitability, and the availability of more sensible and decisive options, it retained a certain allure due to its offensive nature and the pessimism of pre-war thinking, which expected offensive operations to be short-lived, costly in casualties, and unlikely to be decisive. Accordingly, the Aufmarsch II West deployment was changed for the offensive of 1914, despite its unrealistic goals and the insufficient forces Germany had available for decisive success. Moltke took Schlieffen's plan and modified the deployment of forces on the western front by reducing the right wing, the one to advance through Belgium, from 85% to 70%. In the end, the Schlieffen plan was so radically modified by Moltke, that it could be more properly called the Moltke Plan.
The plan called for the right flank of the German advance to bypass the French armies concentrated on the Franco-German border, defeat the French forces closer to Luxembourg and Belgium and move south to Paris. Initially the Germans were successful, particularly in the Battle of the Frontiers (14–24 August). By 12 September, the French, with assistance from the British Expeditionary Force (BEF), halted the German advance east of Paris at the First Battle of the Marne (5–12 September) and pushed the German forces back some 50 km (31 mi). The French offensive into southern Alsace, launched on 20 August with the Battle of Mulhouse, had limited success.
German soldiers in a railway goods wagon on the way to the front in 1914. Early in the war, all sides expected the conflict to be a short one. In the east, Russia invaded with two armies. In response, Germany rapidly moved the 8th Field Army from its previous role as reserve for the invasion of France to East Prussia by rail across the German Empire. This army, led by general Paul von Hindenburg defeated Russia in a series of battles collectively known as the First Battle of Tannenberg (17 August – 2 September). While the Russian invasion failed, it caused the diversion of German troops to the east, allowing the tactical Allied victory at the First Battle of the Marne. This meant Germany failed to achieve its objective of avoiding a long, two-front war. However, the German army had fought its way into a good defensive position inside France and effectively halved France's supply of coal. It had also killed or permanently crippled 230,000 more French and British troops than it itself had lost. Despite this, communications problems and questionable command decisions cost Germany the chance of a more decisive outcome.
Asia and the Pacific
New Zealand occupied German Samoa (later Western Samoa) on 30 August 1914. On 11 September, the Australian Naval and Military Expeditionary Force landed on the island of Neu Pommern (later New Britain), which formed part of German New Guinea. On 28 October, the German cruiser SMS Emden sank the Russian cruiser Zhemchug in the Battle of Penang. Japan seized Germany's Micronesian colonies and, after the Siege of Tsingtao, the German coaling port of Qingdao on the Chinese Shandong peninsula. As Vienna refused to withdraw the Austro-Hungarian cruiser SMS Kaiserin Elisabeth from Tsingtao, Japan declared war not only on Germany, but also on Austria-Hungary; the ship participated in the defense of Tsingtao where it was sunk in November 1914. Within a few months, the Allied forces had seized all the German territories in the Pacific; only isolated commerce raiders and a few holdouts in New Guinea remained.
The Flight of East Asia Squadron
The German East Asia squadron having been put on the run by the loss of nearly every single colony and potential safe haven in the Pacific were forced to flee across the ocean. Maximilian Von Spree in an attempt to salvage his collected fleet made a beeline for the Americas hoping to take to port in an American country and wait out the war using its neutrality as a shield. Making the assumption the American good favor the German Empire had garnered over the past decade would salvage the fate of his battlegroup. He initially pushed towards California in hopes of putting to port in San Francisco or one of the other west coast ports only to make the decision later to change course to Panama and reach an east coast port in an attempt to get as close to home as possible. When the fleet reached Panama. While multiple ships were able to put through the Panama canal, the German battlegroup was also forced to abandon a few ships as the British closed, scuttling them to prevent their capture. The British unwilling to test the American fleet on the other side of the Panama canal issued diplomatic objections to the American government for "aiding the enemy" but with the recent declaration of American neutrality as well as the "Neutral Haven Act" which allowed ships from all nations to use American ports for limited repair and resupply as well as some shore leave, the British were unable to truly challenge the US in this regard as the offering was open to British ships and sailors as well
When closing on the port of Norfolk, a young British Captain by the name of Alexander Marshall a newly rising captain which had seen distinguishing action off the coast of Germany just a month previous. Considered hot headed and cocky, this attitude became his downfall as when the German East Asia squadron moved to take the offer of American safe haven in Norfolk he sailed up with his battlegroup of two British Dreadnoughts, a battle cruiser, and four destroyers which were under orders to sink the German battlegroup at all costs with a standing order to violate neutrality if need be.
Under the impression the United States would not sally forth to challenge the British Navy Captain Marshall sailed forth is his battlegroup opening fire on the German task force within American waters. The USS Nevada the only ship with sufficient crew and armaments to challenge the British task force came out of port. Commander William S. Sims having been awarded the command just a month previous was a man determined to not allow this gross violation of American soveriegnty to go unchallenged. He struck his colors, raising the US flag as he began to pass the HMS superb broadside. Captain Marshall on the Superb was under the impression the US ship would sail right by and this was a warning rather than a potential attack. This turned out to be an entirely wrong assumption. Commander Sims trained all the turrets of the Nevada on the Superb and fired. The HMS Superb initially looked as if it had weathered the salvo but when no return fire came, and the Ship began to list heavily to the Port, the Rest of the British Fleet changed their heading to deal with the Nevada which had just sunk their flagship. The Nevada then turned its guns on the British fleet and fired a singular Warning shot across the Bow of the HMS Colossus.
The British fleet scrambled having been totally unexpecting an American Challenge, much less the sinking of their flagship. Lacking a central commander the British Fleet turned to fight the Nevada and deal with the greater threat rather than the fleeing german battlegroup.The Captain of the Colossus immediately gave orders to engage the USS Nevada only to be greeted with a shot that glanced off the Ship off into the water. The SMS Dresden had turned to aid the Nevada. The captain of the SMS Dresden, a german ship returning to aid the USS Nevada, Fritz Lüdeck realized what he was doing and turned his ship to open another salvo at the HMS Colossus. The USS Nevada began to retreat back toward Norfolk as the German cruiser ran interference. In a show of courage the German Cruiser faced off against the British Battle group alone. German survivors attest to US servicemen saluting the SMS Dresden and her crew as the American Super-Dreadnought pulled off and pushed ahead back toward Norfolk firing some covering shots from its cannons as it withdrew.
Captain Lüdeck realizing the American ship had not only saved the lives of him and all his comrades, but was challenging the British by itself, rushed to turn the ship around to aid the American Ship. Lüdeck missed the warning shot as he tried to give orders to ready the ship for a last stand. The USS Nevada on its withdraw from the battle gave its salute to the SMS Dresden and Captain Lüdeck ordered that all guns be brought to bear on the HMS Colossus. The Dresden presenting as little a profile as possible opened fire on the Colossus exclusively in an attempt to score a lucky hit. While some minor damage was incurred the Colossus returned fire with two solid hits on the Dresden. Lüdeck, wounded but still in the fight ordered the ship to charge full into the Colossus and for weapons to be handed out to the Crew. More ships from the British fleet now with clear sight lines of the Dresden opening fire with only one hit. The Dresden itself still surged forward at full steam with fires raging across part of the ship. Closing on the Colossus, the captain fired one more salvo on the Dresden before the German cruiser slammed into the British ship full force. In a final attempt to lock down the British battleship, the German crew began to board the ship as best they could and a full force close quarters engagement broke out between the crews of Colossus and the Dresden.
Unable to actively engage the Dresden due to its proximity to the Colossus, the Remainder of the British fleet remained at a careful distance. The crew of the Dresden fought valiantly and worked toward taking key parts of the British Dreadnought, The British crew while totally unprepared for the ramming by the Dresden, or the boarding of the Colossus, fared extremely well after the initially attack. Outnumbering the German crew by more than two to one the British were able to fend off attacks except for a dedicated attack to take the Magazine of the British ship. The German Captain himself led the final charge to take the British magazine after realizing his rear guard had retreated from their defensive positions guarding their backs on the upper decks. While managing to take the Magazine, the British were able to corner Captain Lüdeck who held the British at a standstill with intent to destroy the magazine and bring both ships and their crews with them. After just an hour of intense close quarters combat, US naval forces from the Coastal patrol, created as a response to prevent such actions as this, arrived to help handle the situation. Five destroyers at full steam from the south with the Battleships New York, Texas, and Arkansas all came into the local area. The USS Nevada also under the full intent to protect the US coast came back out from port to meet the British Fleet. The British not wanting to abandon the Colossus to capture or destruction attempted to stay and guard the ship as it fought off German boarders but after multiple warning shots and recognizing their new inferiority to the US fleet in the area were forced to abandon the Colossus unable to even attempt to save the crew.
Just three hours after the engagement, the British had lost two Battleships, the HMS Superb, and the HMS Colossus to the Americans. Within days, news of the battle between American and British forces spread and an international crisis began to Arise. The British had violated the neutrality and good will of another great power. While insisting the leader of the task force had been acting of his own accord, US presentation of written orders to fire on the German East Asia squadron even if it violated neutrality (corroborated by the Captain of the HMS Colossus) stirred up an immense resentment and anger toward the British who may have started a conflict they very well could not finish.
Some of the first clashes of the war involved British, French, and German colonial forces in Africa. On 6–7 August, French and British troops invaded the German protectorate of Togoland and Kamerun. On 10 August, German forces in South-West Africa attacked South Africa; sporadic and fierce fighting continued for the rest of the war. The German colonial forces in German East Africa, led by Colonel Paul von Lettow-Vorbeck, fought a guerrilla warfare campaign during World War I and only surrendered two weeks after the armistice took effect in Europe.
Indian Support for the Allies
Contrary to British fears of a revolt in India, the outbreak of the war saw an unprecedented outpouring of loyalty and goodwill towards Britain. Indian political leaders from the Indian National Congress and other groups were eager to support the British war effort, since they believed that strong support for the war effort would further the cause of Indian Home Rule. The Indian Army in fact outnumbered the British Army at the beginning of the war; about 1.3 million Indian soldiers and laborers served in Europe, Africa, and the Middle East, while the central government and the princely states sent large supplies of food, money, and ammunition. In all, 140,000 men served on the Western Front and nearly 700,000 in the Middle East. Casualties of Indian soldiers totaled 54,746 killed and 88,246 wounded during World War I. The suffering engendered by the war, as well as the failure of the British government to grant self-government to India after the end of hostilities, bred disillusionment and fueled the campaign for full independence that would be led by Mohandas K. Gandhi and others.
Military tactics developed before World War I failed to keep pace with advances in technology and had become obsolete. These advances had allowed the creation of strong defensive systems, which out-of-date military tactics could not break through for most of the war. Barbed wire was a significant hindrance to massed infantry advances, while artillery, vastly more lethal than in the 1870s, coupled with machine guns, made crossing open ground extremely difficult. Commanders on both sides failed to develop tactics for breaching entrenched positions without heavy casualties. In time, however, technology began to produce new offensive weapons, such as gas warfare and the tank.
Just after the First Battle of the Marne (5–12 September 1914), Entente and German forces repeatedly attempted manoeuvring to the north in an effort to outflank each other: this series of manoeuvres became known as the "Race to the Sea". When these outflanking efforts failed, the opposing forces soon found themselves facing an uninterrupted line of entrenched positions from Lorraine to Belgium's coast. Britain and France sought to take the offensive, while Germany defended the occupied territories. Consequently, German trenches were much better constructed than those of their enemy; Anglo-French trenches were only intended to be "temporary" before their forces broke through the German defences.
Both sides tried to break the stalemate using scientific and technological advances. On 22 April 1915, at the Second Battle of Ypres, the Germans (violating the Hague Convention) used chlorine gas for the first time on the Western Front (but not its first wartime use). Several types of gas soon became widely used by both sides, and though it never proved a decisive, battle-winning weapon on the Western Front, poison gas became one of the most-feared and best-remembered horrors of the war. Tanks were developed by Britain and France, and were first used in combat by the British during the Battle of Somme on 15 September 1916, with only partial success. However, their effectiveness would grow as the war progressed; the Allies built tanks in large numbers, whilst the Germans employed only a few of their own design, supplemented by captured Allied tanks.
The American intervention
By April of 1915 the US president Woodrow Wilson made the decision to openly and actively deliver supplies, escorted by the US navy to Germany. The supply fleet carrying munitions, food, medicine among other things set sail during late April 1915 and reached the British blockade in early May. The British ordered the supply fleet to stop for seizure, but under orders from the US government the ships began to run the blockade. Back in Washington weeks earlier, Wilson had designed a gamble, which would decide American entry into the war. With a population already angry at the British for the violation of its neutrality, President Wilson was already able to rally public support for the war, with many moderates already agreeing that this violation would not stand. He would run the British blockade, delivering supplies to the German Empire, if the British fired, or stopped the ships and seized them, the American entry to the war was assured, if the British let the ships go, the US would play both sides and supply both. He received his answer on May 4th 1915. The Supply fleet had been seized and the US destroyer escorts had sought shelter in German ports. On May 5th Congress declared war on the British. This led to the remaining Entente Powers declaring war on the United States in short order.
The entrance of the United States in the war, prompted a mass scare of the various public of the Entente Powers. The British, however, drastically stepped up their recruitment efforts, and resigned themselves to the Western Front stalemate, transferring multiple Divisions to Canada to meet the United States in Battle. The United States, while maintaining a small military, mobilized its vast population and resources in short order. The United States, with only an army force of roughly 150,000 by the wars start, organized the American Expeditionary Force out of its existing forces, planning on quickly taking Canada's major cities and then taking the fight to the Entente abroad was stopped almost immediately, as Canadian veterans from the Western Front, joined by British regulars the Canadian forces crossed the Border relatively quickly attacking Detroit and Buffalo in short order. The AEF met the British and the Canadians quickly to prevent the capture of and US cities, culminating in the first two battles of the North American Theatre. The Battle of Detroit, and the Battle of Buffalo led to extremely brutal and bloody results as nearly 60,000 troops on both sides were killed and wounded in Detroit, and another 30,000 in Buffalo forcing the British and Canadians to retreat back across the Canada. The battles themselves lasted roughly a month each and the US began to realize this may not be a quick and easy war. However, within three months, the US had managed to recruit and train nearly 300,000 new soldiers, and with the passing of the Selective Service act, the US numbers swelled to nearly three million, with nearly 2.5 million being draftees, and nearly 500,000 being volunteers.
By September of of 1915 the AEF began to move its forces into Canada only to meet stiff and dedicated resistance from Canadian and British forces, who had applied their lessons from Europe to Canada. Trench lines, prepared by the Entente Forces met the first US invasion of Canada with great success. The First Toronto Offensive ended in a rough and brutal stalemate favoring the British, the US forces taking some queues from the Germans adopted their own trench lines with the expressed intent of preventing another attack on US soil from this area. It also saw the first usage of Gas during the war which offset the relative differences in numbers the US was able to employ against the canadians. Many smaller and medium sized skirmishes happened near the Toronto trench lines, with much of the smoke and noise being able to be heard from the outer city limits. The only notable victory of the initial campaigns in Canada was the extremely short siege of Vancouver, which saw the US attack, and siege, and occupy Vancouver and the surrounding area, in less than three weeks. However, the issue remained that US forces would never be able to cross the Canadian wilderness to hit Canada on the flank due to the outright lack of roads and proper logistics in enough numbers to do so. The US considered some possibilities but was content with claiming victory in the Canadian West as opened up a corridor to Alaska.
At the start of the war, the German Empire had cruisers scattered across the globe, some of which were subsequently used to attack Allied merchant shipping. The British Royal Navy systematically hunted them down, though not without some embarrassment from its inability to protect Allied shipping. For example, the German detached light cruiser SMS Emden, part of the East-Asia squadron stationed at Qingdao, seized or destroyed 15 merchantmen, as well as sinking a Russian cruiser and a French destroyer. However, most of the German East-Asia squadron—consisting of the armoured cruisers Scharnhorst and Gneisenau , light cruisers Nürnberg and Leipzig and two transport ships—did not have orders to raid shipping and was instead underway to Germany when it met British warships. The German flotilla fled to the United States in an attempt to seek safe haven and hold up until an opening occured or the war ended.
Soon after the outbreak of hostilities, Britain began a naval blockade of Germany. The strategy proved effective, cutting off vital military and civilian supplies, although this blockade violated accepted international law codified by several international agreements of the past two centuries. Britain mined international waters to prevent any ships from entering entire sections of ocean, causing danger to even neutral ships. Since there was limited response to this tactic of the British, Germany expected a similar response to its unrestricted submarine warfare.
The Battle of Jutland (German: Skagerrakschlacht, or "Battle of the Skagerrak") developed into the largest naval battle of the war. It was the only full-scale clash of battleships during the war, and one of the largest in history. The Kaiserliche Marine's High Seas Fleet, commanded by Vice Admiral Reinhard Scheer, fought the Royal Navy's Grand Fleet, led by Admiral Sir John Jellicoe. The engagement was a stand off, as the Germans were outmanoeuvred by the larger British fleet, but managed to escape and inflicted more damage to the British fleet than they received. Strategically, however, the British asserted their control of the sea, and the bulk of the German surface fleet remained confined to port until the American fleet began to encroach in the Western Atlantic and Mediterranean severely straining Entente resources.
The nature of submarine warfare meant that attacks often came without warning, giving the crews of the merchant ships little hope of survival. The United States launched a protest, and Germany changed its rules of engagement. After the sinking of the passenger ship RMS Lusitania in 1915, Germany promised not to target passenger liners, while Britain armed its merchant ships, placing them beyond the protection of the "cruiser rules", which demanded warning and movement of crews to "a place of safety" (a standard that lifeboats did not meet).
War in the Balkans
Facing off against Russia, Austria-Hungary could spare only one-third of its army to attack Serbia. After suffering heavy losses, the Austrians briefly occupied the Serbian capital, Belgrade. A Serbian counter-attack in the Battle of Kolubara succeeded in driving them from the country by the end of 1914. For the first ten months of 1915, Austria-Hungary used most of its military reserves to fight Italy. German and Austro-Hungarian diplomats, however, scored an advantage by persuading Bulgaria to join the attack on Serbia. The Austro-Hungarian provinces of Slovenia, Croatia and Bosnia provided troops for Austria-Hungary, in the fight with Serbia, Russia and Italy. Montenegro allied itself with Serbia.
Bulgaria declared war on Serbia, October 12 and joined in the attack by the Austro-Hungarian army under Mackensen's army of 250,000 that was already underway. Serbia was wipuied out in a little under than a month, as the Central Powers, now including Bulgaria, sent in 600,000 troops total. The Serbian army, fighting on two fronts and facing certain defeat, retreated into northern Albania. The Serbs suffered defeat in the Battle of Kosovo. Montenegro covered the Serbian retreat towards the Adriatic coast in the Battle of Mojkovac in 6–7 January 1916, but ultimately the Austrians also conquered Montenegro. The surviving Serbian soldiers were evacuated by ship to Greece. After conquest, Serbia was divided between Austro-Hungary and Bulgaria.
In 1915 the Allies landed forces in Greece proper with the pro-German king being "indisposed" as the pro allied government allowed a Anglo-French task force to land. Eventually the pro-German King Constantine I abdicated in favor of his son Alexander which joined the shortly thereafter. The French having committed the majority of the forces, personally faced off against the Bulgarian forces which while they were preoccupied in Romania had managed not only to embark on a rather daring offensive, but had gained unexpected Austro-Hungarian and eventually Ottoman support as the Central Powers began to push the Allies out of Greece.
With the collapse of the Greek forces in August of 1915 the Central Powers had achieved a critical victory in presenting a united coastal defensive line to the Allies as the French, British, and eventually Italian navies were never able to gain much success in further invasions. The collapse of the Balkan theatre was especially crucial as it decisively crushed any further Serbian resistance and the Greeks were more than happy to avoid the further ravaging of their country.
On 2 August 1914 the Ottoman Empire signed the secret Ottoman–German Alliance, agreeing to enter the war on the side of the Germany, should Russia intervene militarily.They then joined battle on when they attacked the Russian Black Sea coast on 29 October 1914. This prompted Russia and its allies, Britain and France, to declare war on the Ottomans in November 1914.
The Ottomans threatened Russia's Caucasian territories and Britain's communications with India via the Suez Canal. As the conflict progressed, the Ottoman Empire took advantage of the European powers' preoccupation with the war and conducted large-scale ethnic cleansing of the indigenous Armenian, Greek, and Assyrian Christian populations, known as the Armenian Genocide, Greek Genocide, and Assyrian Genocide.
The British and French opened overseas fronts with the Gallipoli (1915) and Mesopotamian campaigns (1914). In Gallipoli, the Ottoman Empire successfully repelled the British, French and Australian and New Zealand Army Corps (ANZACs). In Mesopotamia, by contrast, after the defeat of the British defenders in the Siege of Kut by the Ottomans (1915–16), British Imperial forces reorganised and captured Baghdad in March 1917 only to be Ousted by newly arrived American support shortly thereafter. The British were aided in Mesopotamia by local Arab and Assyrian tribesmen, while the Ottomans employed local Kurdish and Turcoman tribes.
Further to the west, the Suez Canal was defended from Ottoman attacks in 1915 and 1916; in August, a German and Ottoman force was defeated at the Battle of Romani by the ANZAC Mounted Division and the 52nd (Lowland) Infantry Division. Following this victory, an Egyptian Expeditionary Force advanced across the Sinai Peninsula, pushing Ottoman forces back in the Battle of Magdhaba in December only to be reversed Battle of Rafa on the border between the Egyptian Sinai and Ottoman Palestine in January 1917 with the movement of force pushing up to the Sinai and Suez canal shortly thereafter.
The battles in the Caucasus saw mostly Russian successes due to poor leadership on the part of the Ottomans, and the terrain which played heavily to their advantage. Enver Pasha, supreme commander of the Ottoman armed forces, was ambitious and dreamed of re-conquering central Asia and areas that had been lost to Russia previously. He was, however, a poor commander, launched an offensive against the Russians in the Caucasus in December 1914 with 100,000 troops; insisting on a frontal attack against mountainous Russian positions in winter. He lost 86% of his force at the Battle of Sarikamish.
While the Russians did in fact plan on further attacks into the Ottoman Empire the Russian Empire dissolved as the Russian Civil war broke out and the Caucasian army collapsed and returned home. However with the Ottomans undergoing a vast array of sweeping reforms brought about by Ataturk and the immense American influence in the area prevented any major offensive to seize these territories and they de facto stayed under the umbrella of Russian influence post war.
In December 1914 the Ottoman Empire, with German support, invaded Persia (modern Iran) in an effort to cut off British and Russian access to petroleum reservoirs around Baku near the Caspian Sea. Persia, a neutral country, had long been under the spheres of British and Russian influence. The Ottomans and Germans were aided by Kurdish and Azeri forces, together with a large number of major Iranian tribes, such as the Qashqai, Tangistanis, Luristanis, and Khamseh, while the Russians and British had the support of Armenian and Assyrian forces. The Persian Campaign was to last until 1919 and end in failure for the Ottomans and their allies. However the Russian withdrawal from the war in 1917 led to Armenian and Assyrian forces, who had hitherto inflicted a series of defeats upon the forces of the Ottomans and their allies, being cut off from supply lines, outnumbered, outgunned and isolated, forcing them to fight and flee towards British lines which were further south towards Egypt and eventually just led to a tacit withdraw to the British Raj.
The eventual accelerated collapse of the Ottoman empire during and post war was brought about by the dual Turkish and Arab Revolts led by Mustafa Kemal Ataturk, and multiple lesser known Arab leaders finally settling on Prince Faisal the only surviving member of the Hashemite dynasty. Ataturk and Faisal both purporting some sort of new state with Ataturk dead set on leveling the Turkish dominance of a new unified state underwent a series of negotiations to secure the unity and declaration of the Union of Sovereign Islamic States following the war.
The Italians while nominally on the side of the Central Powers, refused to join the war which was highly perceived as offensive. While not overly detrimental to the plans of the Germans and Austrians, the loss of manpower was somewhat felt as it required rethinking the plans of the southern Flank. Italy in particular had taken this time to weave a series of agreements with the Entente to secure its joining. This included territory held by Austria which was considered Italian, and even some new colonial territory. The Italians promptly joined in 1915 just about a year after the war started and opened up a front on the Austro-Hungarian military.
The Italian Front opened shortly thereafter which saw a small initial advance by the Austrians only to secure both sides of the Alps and hold a defensive line. This led to the Italians being forced to assault the heavily fortified Alpine defensive lines set up by the Austro-Hungarian Empire. While outnumbering their Austrian counterparts almost three to one the defensive area made the number makeups almost a non-issue. This was noted in the early Battles of Isonzo which saw the Italians thrown back only to see the Austrians try to advance during the Battle of Asiago which also turned into a high level stalemate.
On 2 August 1914 the Ottoman Empire signed the secret Ottoman–German Alliance, agreeing to enter the war on the side of the Germany, should Russia intervene militarily which happened in short order. They then joined battle on when they attacked the Russian Black Sea coast in October of 1914. This prompted Russia and its allies, Britain and France, to declare war on the Ottomans in November 1914.
The Ottomans threatened Russia's Caucasian territories and Britain's communications with India via the Suez Canal. As the conflict progressed, the Ottoman Empire took advantage of the European powers' preoccupation with the war and conducted large-scale ethnic cleansing of the indigenous Armenian, Greek, and Assyrian Christian populations, known as the Great Near East Genocide, which was lumped with the Great Balkan War which established Bulgarian regional control of the Balkans.
The British and French opened overseas fronts with the Gallipoli (1915) and Mesopotamian campaigns (1914). In Gallipoli, the Ottoman Empire successfully repelled the British, French, and Australian and New Zealand Army Corps (ANZACs). In Mesopotamia, by contrast, after the defeat of the British defenders in the Siege of Kut by the Ottomans (1915–16), British Imperial forces reorganised and captured Baghdad in March 1917 but were evicted soundly by the intervention of the Levantine Expeditionary Force sent by the United States which had been organizing in Turkey in months previous.
Further to the West, the United States, German, and Ottoman forces were unable to breach the Suez Canal but did manage to keep pressure on it for long period of time with multiple assaults in 1915, 1916, 1917, and 1918 almost all of them preceding major assaults or operations by the Central Powers. These served the purpose of redistributing force across the conflict and prevent the full strength of any one power from coming to bear against any single one of their allies.