Morgenthau recounted the key historical events. President Theodore Roosevelt negotiated an end to the Russo-Japanese War that maintained the balance of power in Asia. The Washington Naval Treaty of 1922 effectively ended the British-Japanese alliance and sought to limit the rising power of Japan. In 1931, the so-called Stimson Doctrine, which refused to recognize territorial acquisitions gained by force, was aimed at Japanese imperial conquests. In 1941, President Franklin Roosevelt directed U.S. policy at countering the expansionist designs of Japan, resulting in the attack on Pearl Harbor and U.S. entry into the Second World War. In the immediate aftermath of World War II, U.S. policy sought to promote a strong China as a bulwark against a revival of Japanese expansion. That policy broke down when the communists seized power in China. Since then, U.S. policy focused on containing communist China.