Second, "rebalancing" is impossible without allies. Between the United States and China lie Japan, South Korea and Taiwan, all with strong ties to Washington. These three represent the third-, 13th- and 20th-largest economies in the world, and all have strong militaries. Each faces a much more immediate threat from China than does the United States. Washington's commitment to the region must not go beyond the willingness of these countries to defend their own interests. The Japanese prime minister's recent advocacy of greater defense spending is a hopeful sign. Similar commitments should be expected from South Korea and Taiwan. Regional integration is vital. The Obama administration should continue to foster military cooperation among Asian nations and must also advocate more vigorously for the Trans-Pacific Partnership, a free trade agreement consisting primarily of democratic counties.