It would be difficult to overstate the political effects of World War I. It was, after all, a “world war,” and one that fundamentally transformed much of the existing international structure while planting the seeds of another, more devastating war that would follow. For one, the old empires—Austro-Hungarian, Ottoman, German, and Russian—all collapsed, although the Russian Empire would be painstakingly and bloodily rebuilt by the regime that replaced the monarchy. In their place emerged the international order that would remain largely intact for the next 70 years.
Borders shifted as the Great War’s victors seized territories from the losers. The modern Middle East was forged out of the remnants of the Ottoman Empire, although the French and British diplomats who drew the map of the newly-reconfigured region planted the seeds of future conflicts among Arabs, Kurds, Persians, Jews, and others.
The formation of the Soviet Union (in effect, a reassembling of the old Russian Empire with the added phenomenon of mass forced migrations of nationalities like the Tatars) represented a serious challenge to the empires that survived the war, mainly that of Great Britain, due to its avowed support of what came to be called “movements of national liberation.”
One of the most consequential effects of World War I was the evolution of Germany, shorn of important territories like the region on the French border known as Alsace-Lorraine, which was turned over to France, as was control of the vital Ruhr industrial region. The loss of these deprived Germany of the means to pay the onerous reparations that were demanded of it in the Versailles Treaty. The treaty’s stipulations are viewed as one of the main reasons that the Weimer Republic—Germany’s short-lived democratic government—failed, opening the door to the National Socialist Party of Adolf Hitler.
As a direct result of that disastrous war, the old monarchies of Europe either disappeared or were sublimated to other forms of government. The Bolsheviks, of course, slaughtered the Russian czar and his family to ensure that the Romanov Dynasty would never rise again, replacing one dictatorship with an even more brutal one, especially following Joseph Stalin’s rise to power. Conversely, the fall of the Ottoman Empire opened the door to the establishment of a Turkish Republic that would survive the next world war but whose founding doctrine of secularism would be wiped away with the emergence of the Islamist Justice and Development Party in the early 2000s.
These could be considered the main political effects of World War I. The collapse of old empires, the emergence of a communist regime in Russia, the failure of the Weimer Republic in Germany (accompanied by Adolf Hitler’s rise to power on a platform of hate and expansionism), and the redrawing of borders across the Middle East.