The United States and the United Kingdom had been the principal suppliers of military materiél to India and Pakistan since 1947. Both India and Pakistan were Commonwealth republics. While India had pursued a policy of nominal non-alignment, Pakistan was a member of both CENTO and SEATO and a purported ally of the West in its struggle against Communism. Well before the conflict began, however, Britain and the United States had suspected Pakistan of joining both alliances out of opportunism to acquire advanced weapons for a war against India. They had therefore limited their military aid to Pakistan to maintain the existing balance of power in the subcontinent. In 1959, however, Pakistan and the United States had signed an Agreement of Cooperation under which the United States agreed to take "appropriate action, including the use of armed forces" in order to assist the Government of Pakistan at its request. By 1965, American and British analysts had recognised the two international groupings, CENTO and SEATO, and Pakistan's continued alliance with the West as being largely meaningless.