The Decade of Ten Wars, also referred to as the Warring Twenties, was a series of conflicts that took place in the 1920s. Many factors have been attributed to the largest period of warfare since the Middle Ages, but it has been widely accepted the main cause was the immense tension between the nations at the time. It is often regarded as miraculous one or more of the wars during this time didn't escalate into a wider conflict. The main contributor which prevented that was the betrayal of fellow Central Power Austria-Hungary by Italy during the Alpine War. The betrayal would ensure other alliances had their days numbered, as nations began looking over their shoulder more often, and distrust among allies grew.
- Russian Civil War, 1920-1922: communist groups began arising in Russia in the late nineteenth century. By the late 1910s, despite concessions made by the Czar, many felt the Imperial Russian government wasn't doing enough. In 1920, protests against the Czar turned violent. When military forces attempted to clear them, shots were fired and the situation devolved into a massacre. After the second time protesters were killed at the hands of the Russian government, the people rose up. Although initially beaten in several battles, the communist rebels later made headway after Finland successfully secured their independence. After two years, Czar Nicholas II was captured and executed. His daughter, Anastasia, fled to Germany, as the Hohenzollerns were relatives of the Russian Royal family (Kaiser Wilhelm II and Czar Nicholas II were cousins, and signed letters to each other as "Willy" and "Nicky" respectively). The from Germany, she continued to claim the Russian throne as rightfully hers. This was a contributing factor for the new Soviet Russia's decision to go to war with Germany several years later.
- Second Franco-Prussian War, 1921-1922: following France's humiliating defeat at the hands of the fledgling German Empire in 1871, and the subsequent loss of parts of the Alsace and Lorraine territories, France had always been anxious to get back at Germany, to get revenge. France made allies with Great Britain and Russia, hoping to squeeze Germany should war come. But their chance never came. Following the Alpine War, the trust between allies was shaken, and after the Russian Empire fell into civil war, and Great Britain becoming more distant from France, it was clear that any war between it and Germany would be done alone. Plans for a preemptive attack on Germany were drawn up, calling for a full-scale invasion of Alsace-Lorraine. German spy's within France learned of this and leaked it to Germany. Germany called for a mobilization of the army and navy, prompting France to do the same. The United Kingdom had agreed to defend Belgian neutrality in the Treaty of London, the UK had become increasingly disinterested in "continental politics". As a result, the previous year's had seen Belgium coming under french influence, along with Luxembourg. Germany declared war in late 1921, invading France via Belgium quickly overrunning its defenses. With the bulk of their forces now outflanked, the French army began to fall apart in short order. In a matter of months, German troops marched into Paris, and France surrendered. In the ensuing peace, Luxembourg was annexed into Germany. France fell into a period of instability, which would result in the Second French Revolution at the end of the decade.
- Great South American War, 1921-1924: following the Scramble for Africa, some European powers wished to expand their influence into South America, despite the risk of the United States intervening via the Monroe Doctrine. In 1919, a German-backed coup overthrew the republican government of Brazil. Almost immediately, the new Royal government began reclaiming Uruguay as part its territory. Fearful of an expansionist Brazil, Argentina requested Brazil to stop. These requests were rejected. When Uruguay decided to take their chances and reject re-assimilation. Brazil invaded in late 1921, promoting Argentina to declare war as well. With Argentinas intervention, what would have been an easy victory dragged out. Brazils and Argentinas European-built battleships clashed only once during the course of the war, in the Battle of the River Plate, which ended tactically inconclusive. For three years Brazil advanced into Uruguay, ultimately overrunning it in 1924. The war was costly, and at the price of increasingly tense relations with Argentina, Brazil's new imperial government was secured.
- Russo-German War, 1923-1925: Princess Anastasia continued to claim to be the heir to the Russian throne, a claim Germany recognized. Kaiser Wilhelm II granted her an estate in the Prussian countryside where she resided. The Germans acceptance of her angered the new Soviet Government, who made repeated demands to return her for crimes against the Russian people, and every time Germany refused. The issue culminated in a declaration of war by Russia in the summer of 1923. Germany, whose military was still partially mobilized after the Second Franco-Prussian War, redeployed its forces to the Russian border. The Russian army pushed into East Prussia, but that turned out to be their high-water mark. German troops counterattacked, taking Warsaw in early 1924. Further offensives later took most of Russia's Baltic Sea coast. Following the defeat of the Russian army at the Battle of Vilnius, and the utter destruction of the Russian navy at the Battle of the Gulf of Riga, Russian sued for peace, and ceded huge swaths of territory. This territory would be organized into the German puppet states of Poland, Lithuania, Latvia, and Estonia.
- Franco-Italian War, 1924-1925: Soon after the Second Franco-Prussian War, France began experiencing internal turmoil. The republican government came under increasing fire, being called "overly-bureaucratic" and ineffective. Among the unrest, Italian irredentism reared its ugly head once again. The French province of Savoy was on Italy's list of claims. Seeing an opportunity to avenge their defeat in the Alpine War, Italy demanded Savoy be handed over. France, its government wishing to show it still has some might, refused. Italy invaded the region in October 1924. The French army put up little resistance, only those still loyal to the French Republic showed up to fight. The pitiful fight the French put up lead to Savoy being overrun. In what would turn out to one of the last acts by the French Republican government, Savoy was ceded to the Kingdom of Italy. The victory would help dim the loss of Lombardy-Venetia, though that remained their focus.
- Second Crimean War, 1925-1926: often considered an extension of the Russo-German War, the Second Crimean War was the result of the increased voice of ethnic minorities, namely Ukrainians, in the United States of Greater Austria. After the outset of hostilities between Germany and Soviet Russia, Poles and Ukrainians began pushing for intervention on the side of their German allies, for the goal of freeing their ethnic brethren. Some militia groups were hastily formed, and crossed the border to assist the German army. Austria began seriously contemplating the thought following the German capture of Warsaw. As the war between Germany and Russia was winding down, Austria decided it was opportune moment, and declared war in April of 1925. The off-guard Russians were overwhelmed, the ethnic Ukrainian region was secured following the brief Siege of Kiev in November, before the worst of the infamous Russian Winter. The concessions to Austria were then included in the Treaty of Kursk.
- Greco-Ottoman War, 1925-1927: Like Italy, Greece had its own irredentist movements following its independence. It lay claims to parts of Bulgaria, Albania, and the Ottoman Empire. As ethnic troubles began to broil in the Balkans, Greece saw its chance and began building its forces. Following its conquest of Savoy, Italy gave Greece its assurance Italy will back Greece's claims. The war began as a preemptive strike on Ottoman naval facilities, followed by the landing of Greek and Italian troops on the Ottoman Empire's western shore. After the initial success, though, the Ottomans began pushing back as their war machine kicked into gear. Constantinople, the ultimate prize, was fought for viciously, but ultimately shared the fate of Venice; devastated by the battle, but eventually fell to the attackers. After the fall of Constantinople in mid-1926, the morale of the Ottomans plummeted, and several more successive battles later lead to the Ottomans suing for peace. It was a peace which forced them to relinquish much of its Aegean coastline, and would thrust Greece onto the world stage.
- Third Balkan War, 1927-1929: The Balkan Peninsula was a hotbed of conflict, two wars within a matter of years help brew a hostile environment. Bulgaria soon worked an alliance with the Triple Alliance, which was reorganized into the Central Powers following the Alpine War. After Greece's decisive victory over the Ottoman Empire, the odds of intervention by either of them in a war, and Bulgaria soon looked to regain territory lost in the Second Balkan War. Bulgaria declared war on Serbia in August 1927, a declaration Serbia, Romania, and Montenegro soon returned. The United States of Greater Austria declared war on the Balkan Alliance soon after. As a precaution, army units from the ethnic Serb and Romanian states were not mobilized to not risk ethnic conflict. Montenegro was almost immediately overrun by Austrian troops, and Serbia and Romania were forced to divide their armies between Austria and Bulgaria. It was Bulgaria, in the end, who broke through the lines, and occupied South Dobruja and Macedonia. In the ensuing peace treaty, Montenegro was annexed to the Austrian state of Bosnia and Herzegovina, and Bulgaria was ceded South Dobruja and Macedonia.
- Second French Revolution, 1929-1931: within a matter of years, France was dealt two devastating defeats; first to Germany, in what turned into a repeat of the Franco-Prussian War, and the second against Italy, the increasingly expansionist country looking to avenge the Alpine War. The loss of territory and prestige lead to a drastic drop in support for the Third French Republic. Large portions of the military then turned against the government, blaming the "bureaucratic nonsense" of the republican administration. In mid-1929, during a protest in Paris, loyalist troops were deployed to force them out. The commanders misunderstood their orders, and believed they held authorization to fire on the people. When the crowd proved unreceptive, this is what was resorted to. Several dozen died that day, and sparked an open rebellion. Military units fought within themselves as those loyal to the current government, and the revolutionaries struggled for control. Defections from the loyalist ranks spiked in late-1930, giving the revolutionaries a clear superiority in numbers. The republican government was trapped in Paris when it fell in early-1931, and were forced to resign at gunpoint.
Following the Decade of Ten Wars, Europe laid shattered. Many local economies were devastated, and most national economies took a large hit. Even the United States was hit, as it supplied many countries during the years. When the US began to demand the Europeans repay them for the supplies and material given to them. The situation only worsened as industries were forced to convert from wartime, to much less demanding peace-time, leading to massive lay-offs. Unemployment skyrocketed, good production plummeted. In New York City, many American investors began dumping their European assets in late-1930, seeing them as unstable due to their worsening conditions. What began as a trickle grew and turned into a flood. Many European economies finally crashed in 1932, realizing the threat of war was the main drive behind them. The crash spread around the globe, confidence in all nations' economies wavered, "It's happened there, will it happen here?", was the general fear. Asian markets soon fell, with American ones finally collapsing in early-1933.