Declaration by United Nations
The Big Three—the United Kingdom, the Soviet Union, and the United States—formed a Grand Alliance that was key to victory. They controlled Allied strategy; relations between the United Kingdom and the United States were especially close. The alliance was formalized by the Declaration by United Nations, on 1 January 1942. The Big Three together with China were referred to as a "trusteeship of the powerful", then were recognized as the "Four Powers" in the Declaration by United Nations and later as the "Four Policemen" of the United Nations.