It was the attack of North Korea upon the South on 25 June 1950 that brought the full application of containment to the Asia-Pacific. The attack provided the point at which American global and regional perspectives were joined. The end of the Berlin blockade in May1949 was thought to have stabilized matters in Europe, but since then the Soviet Union had broken the American monopoly by testing an atomic bomb in August and the Chinese communists had declared their victory in October. Notwithstanding Acheson’s attempts to sow dissension between them, Mao and Stalin conclude their treaty of alliance in February 1950. The surprise attack was seen as a turning point, Communism has passed beyond the use of subversion to conquer independent nations and will now use armed invasion and war. Within two days of the invasion Truman had ordered American air and novel forces into action in Korea and announced that the navy would be interposed between Taiwan and the Chinese mainland. He also sent American military advisers to assist the French war in Indo-China.