By early 1952 it had become a central tenet of the Truman administration's Far Eastern policies that China was an aggressive and expansionist power, whose ambitions for regional dominance, encouraged by a Soviet Union content to see American manpower and resources consumed by the inconclusive fighting in Korea, posed a dangerous threat to key American interests. These interests had become enlarged to embrace the rehabilitation and strengthening of Japan, a formal ally once the security treaty came into operation in April 1952, and which through its military-industrial potential was perceived as the principal prize in East Asia. In January 1952, Acheson had avowed to British officials that ‘the heart of the matter in the Far East was to build up sufficient strength so as to hold Japan on the side of the West’, and pointed out the ‘great shift in the world power situation if Japan with its military virtues and industrial capacity went over to the Communist side. While the chances of keeping Japan on the side of the West were not overwhelming, everything had to be done toward this end.’ This primary goal entailed also assuring the security and stability of South East Asia, whose valuable markets and raw materials were important in their own terms to keep out of Communist hands, but also because access to them was seen as crucial to Japanese economic growth and prosperity.