International law evolved to circumscribe the use of armed force with legal restrictions. The forcible acquisition of territory by conquest became illegitimate and individual criminal liability might attach to those who pursued it. In criminalizing war, this treaty played a role in the development of a new norm of behaviour in international relations, a norm that continues to play a role in our current international order. Which is this treaty or pact which also initiated the concept of renunciation and outlawry of war in international law and also served as the legal basis for the concept of crimes against peace and humanity and on that basis, the trials were held which executed the top leaders responsible for starting World War II: