Mexico During World War II Mexico had very good business relations with the United States. They provided a lot of raw materials, which were necessary to support American military needs. In that time the U.S. had an agreement with Mexico specifying that the country would export its resources only to the Allies. After WW II Mexico restricted imports in an attempt to promote domestic growth, while resisting foreign domination. In 1948 the government striving to reverse the unfavorable balance of trade, devalued the peso. Imports not essential for industrial development were sharply restricted. They did this to reach a stage of self-sufficienc