The structure of international trade is determined not only by market forces, but also by the political objectives of states. Weak states participate least in the open international trading system. The strong states that do participate channel trade largely within regional trading blocks. The major states in Europe and East Asia have an incentive to diminish their dependence on the hegemonic power, that is, the United States, which has reacted with its own regionalism (NAFTA). Moreover, regionalism is interpreted as a strategy that reduces states' exposure to major shocks in the global economy. Additionally, it permits them to support weak sectors of their economies at a regional level without entirely undermining the long-term growth benefits of international trade, since a substantial degree of autarky is more feasible and efficient at a regional rather than at the national level.