The completion of colonial conquest of much of the world (see the Scramble for Africa), the devastation of World War I and World War II, and the alignment of both the United States and the Soviet Union with the principle of self-determination led to the abandonment of the right of conquest in formal international law. The 1928 Kellogg–Briand Pact, the post-1945 Nuremberg and Tokyo Trials, the UN Charter, and the UN role in decolonization saw the progressive dismantling of this principle. Simultaneously, the UN Charter's guarantee of the "territorial integrity" of member states.