Treaty of Mutual Cooperation and Security between the United States and Japan
The Sino-Soviet Treaty of Friendship, Alliance and Mutual Assistance included the provision that each side would protect the other from an attack by "Japan or any state allied with it" and the PRC undoubtedly viewed with alarm Japan's role as the principal US military base during the Korean War. The Treaty of Mutual Cooperation and Security between the United States and Japan signed in 1951 also heightened the discouragement of diplomatic relations between the two countries. In 1952 Japan pushed dissension between the two countries even further by concluding a peace treaty with the ROC (Republic of China, or Taiwan) and establishing diplomatic relations with the Taiwanese authorities.