How war became a crime
The Treaty of Versailles, formally ending World War I and establishing a new postwar order, began with a charter for a new organization. Called the Covenant of the League of Nations, the new body was meant to resolve international disputes peaceably and, crucially, it committed members to respect and preserve as against external aggression the territorial integrity and existing political independence of all Members of the League.
That promise, Article X of the Covenant, was the work of then-US President Woodrow Wilson. Wilson chaired the committee at the 1919 Paris Peace Conference that drafted the covenant, and historian John Milton Cooper, in his book Breaking the Heart of the World: Woodrow Wilson and the Fight for the League of Nations, describes Article X as Wilsons singular contribution to the Draft Covenant.
Wilsons Article would help doom the League. Opponents of US entry into the League, like Sen. Henry Cabot Lodge (R-MA), argued that the provision obligated the United States to jump to the defense of any country around the world, entangling it in conflicts it had no part in. Lodge called it the most important article in the whole treaty, which would send the best of our youth on a foolish errand to guarantee the political independence and territorial integrity of every nation on earth.
These skeptics eventually won out. The US would never join the League, a fact that contributed heavily to its eventual failure in the runup to World War II. If remembered at all, the League of Nations is usually remembered as an embarrassing failed experiment. But some of the experiment has succeeded.
Ive been thinking about Article X amid Russias invasion of Ukraine, which obviously and fundamentally threatens the territorial integrity and political independence of that country. No international law stopped Russian troops from crossing the border, but in some ways, this is the exception that proves the rule initially laid down in Article X.
Moscows actions are so shocking precisely because they violate what is now accepted as a strong norm against territorial conquest by nations. And that norm started with idealistic ventures in the wake of WWI, including Article X and an even more utopian effort: the Treaty for Renunciation of War as an Instrument of National Policy, often called the Kellogg-Briand Pact, signed in 1928.
https://www.vox.com/22959938/crime-war-kellogg-briand-ukraine-conquest