The Global War was, in many ways, the sequel to the European War.
The immediate origin of the War was King Albert of Russia's invasion of Ukraine, which, at the time, was a satellite of the Empire of the Three Crowns. Encouraged by the ease with which Ukraine was occupied (an ease which was helped by Ukrainian resentment of Tricoronal rule), he authorized the invasion of the Republic of Siberia to the east.
This brought additional nations into play, and soon, much of the world was engulfed in war.
The North American Theater
In North America, the British alliance was initially quite successful. New England and parts of the upper Midwest fell under Canadian-British occupation, New York City was bombed into ruins, and the government was forced to flee to a more central location, Kansas City. On the other hand, it (temporarily, as the case proved to be) unified the US, as well as her breakaway neighbor, the Republic of the Pacific Coast.
Eventually, American troops reversed the British-Canadian-Mexican advances, and, in the end, occupied essentially all of North America, with the exception of Newfoundland which remained in British hands, and those portions of northern Canada that were occupied by Japan.
Ironically, the success in the War brought about the end of the Unitd States, which was re-formed into the North American Federation along with former British possessions. It also left Mexico in a situation that lead to a socialist takeover in the early 50's.
The European Theater
The European part of the war lasted longer, and was fought far more bitterly. It also had more significant after-effects than the North American theater.
Soon after the war began, the Empire of the Three Crowns fell apart in a civil war. Some factions supported the Russian cause, while others supported the German cause, but most wished to remain outside the War, and instead focus on fighting each other.
The Austrians sought, and received, union with Germany. Seeing the weakness of the Three Crowns, and believing the Anglo-Russo-French alliance to be the winning side, Italy joined their alliance, declaring war on the various remnants of the Empire of the Three Crowns and Germany.
After a string of initial defeats, Germany began to turn the tide. Russia found herself overextended with her war against Japan to the east, while France and Britain found themselves cut off by the German Navy. King Albert of Russia was assassinated in 1944, and his daughter, Elizabeth, became Queen Elizabeth of Russia. Her position was quite precarious, however, as socialist uprisings questioned the wisdom of a monarchy, particularly one with a foreign queen. As German troops finally crossed the Russian border, the socialist uprisings became especially severe. Fearing the same fate as the earlier tsars, Elizabeth and her sister, Princess Margaret, fled incognito, reaching the front lines, where they surrendered to stunned German troops. They were brought to Berlin, where they lived out the rest of the war in a luxurious exile. The Socialists captured Moscow, and declared the formation of the People's Republic of Russia. The People's Republic didn't last very long, threatened by both internal dissent and the steady march of German and Japanese invaders.
The Italians proved to be a weak partner, as German troops poured over the Alps, and down the Italian peninsula. French and British troops desperately tried to hold them back, with the fiercest fighting being in Rome, which was completely destroyed in the fighting. Italy fell by '42.
Late in '44, with German troops holding the south of the country and steadily pushing back the defenders in the east, the French capitulated, King Henri VI signing the ceasefire.
Britain and Russia continued fiercely resisting, though both were cut off from vital supplies.
On September 8, 1946, German scientists perfected the atomic bomb. On November 5, 1946, Kaiser Wilhelm III of Germany reluctantly authorized the use of the atomic bomb against the Russians.
On November 7, 1946, Russian defenders of the city of Smolensk were astonished to see the German attackers suddenly withdrawing. Fearing a trap, the commanding officer in the city ordered the troops to remain where they were, pending orders from higher up. This proved to be a tragic mistake. The next day, a single German bomber, with two fighters as escort flew over the city, and dropped the first atomic bomb, destroying much of the city. Still Russia fought on, and German troops marched through the ruined city (unaware at the time of the dangers of radiation). A second bomb was dropped on Moscow, destroying the Russian government, and effectively ending the war in the east.
The Kaiser threatened Britain with the same fate if they continued to resist. The Irish, long chaffing under British rule, and fearing being punished for their association with the British, declared their independence, and made an independent peace with Germany. German troops occupied the newly-formed Republic of Ireland, and used it as a staging area in a failed invasion of Scotland. Germany was now in a stalemate with Britain. The Kaiser authorized the use of the atomic bomb if the British did not surrender by the end of the year, proclaiming it to Britain.
King Edward VIII refused to deal with the Germans, and, on December 2, the British overthrew Edward, and declared the monarchy abolished. The Republic of Great Britain was proclaimed, and the provisional President of the Republic, Sir Winston Churchill, surrendered to the Germans three days later.
African-Middle Eastern Theater
At the beginning of the war, Germany held no territories in Africa. However, following the Italian collapse, Germany seized her former colonies in Africa, and launched an invasion eastward of British-held Egypt. With joint German-Tricoronal occupation of the Balkans, the Eastern Mediterranean soon became a German lake. The Ottoman Empire, at the time, just barely holding itself together, had been a neutral power. Germany violated the neutrality and quickly swept in to capture the oil-rich territories of the Arab lands. German troops also swept westward to capture French Algeria and into Morocco, neutralizing the British hold on Gibraltar, and gaining complete control of the Mediterranean, upon the destruction of the remaining French naval forces. Algeria was subsequently used as a base for the invasion of southern France.
The Asian Theater
Aftermath of the War
In North America, the War lead to the dissolution of the United States, and the formation of the North American Federation.
In Europe, Germany found herself master of Europe, North Africa and the Middle East. The Greater German Empire covered all of Europe save only Iberia and the Scandinavian states, which were made up of neutral nations. Her troops were in control of the former Empire of the Three Crowns, all the successor states occupied. Her former adversaries were also occupied. The new Republic of Great Britain was also occupied, though Great Britain alone had avoided land battles.
The peace would prove harder than the war. German troops were not welcome anywhere, and frequently had to put down rebellions. The Kaiser looked across the Atlantic to America's experiment in Federation, but rejected the decentralized model in favor of a more centralized one.
In 1950, Germany officially annexed German-speaking regions, such as Austria and Alsace-Lorraine, as well as the Low Countries. In 1951, the Kaiser proclaimed himself Kaiser of Europe, Africa and the Near East, promulgating a United Empire of Greater Europe. Each of the former nations would form a State with some degree of autonomy, some with Kings, some with Presidents, etc. Attempts at restoring the Russian and British crowns were made unsuccessfully.
The United Empire would use a new currency, the European Mark, which was equal to the old German Mark. National militaries would be abolished in favor of a (German-dominated) European military. The powers of the constituent states were strictly limited.
The United Empire proved to be far less successful than the North American Federation. The Republic of Russia seceded in 1956, leading to the Second European War as other nations also declared their independence. By the end of the war, the United Empire was no more. Germany retained control over much of Eastern and Southeastern Europe, as well as northern Italy, which was reformed into the puppet state of the Republic of Lombardy. Germany lost control, however, of Russia itself, as well as Ukraine and Belarus, which, along with Russia, formed the East Slavic Federation. In the west, France (whose monarchy barely survived the War) and Britain remained adamantly independent, forming a close Franco-British Alliance. Italy, too, was a peripheral member of this alliance.
Meanwhile, the NAF-German-Japanese tripartite alliance began to fall apart. The issue of India, nominally independent after the British defeat in the Global War, came between Germany and Japan, as each sought domination of India. The North American Federation, in turn, distrusted both Germany and Japan for their imperialistic ambitions, and their monarchical structures. All three powers began to distrust the others, and feared above all else an alliance of the other two. Nuclear proliferation began in earnest, and a harsh "Cold War" set in.
Franc and Britain soon became allies of North America, and the Franco-German border became one of the more heavily defended lines. Russia fell into a series of civil wars, which eventually lead to the rise of a harsh "Tsar", who declared the rebirth of the Russian Empire, nearly invading Ukraine and Belarus, until Japan convinced him to hold back. Russia soon joined the Japanese camp, desiring the restoration of her Eastern European territories more than that of Siberia.
The later half of the 20th century was therefore characterized by international tensions and a succession of minor wars, many of them effectively by-proxy wars of the three great superpowers.