China has a clear strategy to control the Pacific, west of Hawaii, and challenge the US for dominance in the eastern Pacific. In 1950, the US articulated its strategy to box in China and the Soviet Union. The first line of defence was based on the First Island Chain, enclosing five seas: Okhotsk, Japan, Yellow, East China and South China. Should the communists break through this chain, the Second Island Chain encloses the west Pacific from the Aleutians, Guam, and down to Darwin in Australia. And should the communists break through this, the defence line becomes Aleutians, Hawaii, and down southward.