Might gas warfare have come into widespread use without the Great War? Perhaps, but the huge investment in weapons of mass destruction in 1914–18 left a precedent that could not be eradicated. The use of poison gas is with us still, notably in Syria.
The peace treaties signed at the end of the war left a damaged world with an impossible legacy: they handed over control of German colonies in Africa and the Pacific to the victorious powers and inspired hope around the world that Woodrow Wilson’s notion of self-determination for subject peoples would lead to the end of empires. Not quite. Self-determination was the property of the former nations, such as Czechoslovakia, Hungary, Poland, and Serbia—all predominantly Caucasian—embedded in the German, Austro-Hungarian, Ottoman Turkish, and Russian empires. Populations of color would have to wait until, under the mandate of the imperial powers, they reached the “maturity” needed for self-government. When would that be? Nobody could say.
Besides, no matter what was decided during the postwar peace conference at Versailles, the imperial powers had already made their own plans for the Middle East. In 1915, the British high commissioner in Egypt promised the keeper of the holy sites in Mecca independence for Arabs in return for their participation in fighting the Ottoman empire. Two years later, Britain’s Balfour Declaration promised Zionists the opposite: a Jewish homeland in Palestine. And these incompatible promises were complicated even more by the secret Sykes-Picot Agreement in 1916, which divided the post-Ottoman Middle East between French and British spheres of influence and drew arbitrary borders—in Iraq, for instance—that have caused instability and conflict ever since.
As a result, violence exploded outside of Europe in 1919–21, when people who had served the Allied cause militarily and otherwise discovered that their recompense would be pious words and nothing more. This happened first in Egypt, then India, then Korea, then China. The wartime collapse of the Ottoman empire brought down its sultan, the all-powerful caliph, and created a crisis in Islam, which lost its spiritual center; Muslim-dominated countries remained colonies ruled (often poorly) by imperial powers under the aegis of the League of Nations. The Muslim Brotherhood, founded in Egypt in 1928 to counter Western exploitation of the Islamic world, was the precursor to al-Qaeda.
The Great War cast its geopolitical shadow across the Far East as well. The extent to which the war fueled the continuing hostility between China and Japan is rarely recognized. The problem arose from the Treaty of Versailles. Both nations, traditionally rivals, were among the victorious delegations. China, however, was the weaker power, plagued by internal strife after its 1911 revolution. Japan had helped the Allies during the war, by convoying Australia’s and New Zealand’s troops across the Indian Ocean and by sending naval cruisers to protect the west coast of Canada. At Versailles, Japan tried to exploit its newly acquired leverage, proposing that the charter of the League of Nations include a commitment to racial equality. President Wilson, as a southern-born politician, knew that any such language would ensure the treaty’s defeat in the U.S. Senate. To prevent the Japanese from walking out of the peace negotiations once their request was turned down, the leaders of Britain, France, and the United States backed Japan’s proposal to grant it temporary control—until 1922, as it turned out—of the Chinese province of Shandong, south of Beijing, which the Germans had controlled during the war.