On September 2, 1940, Roosevelt defied the spirit of the Neutrality Acts in reaching the Destroyers for Bases Agreement. In exchange for the use of British military bases in the Caribbean Islands, the U.S. transferred 50 old World War I American destroyers, which were to be used to defend against German submarines. The destroyers themselves held relatively little military importance, but the deal represented a symbolic American commitment to Britain. Later in September 1940, with the backing of both major party presidential candidates, Congress authorized the nation's first ever peacetime draft. Hitler and Mussolini responded to the Destroyers for Bases Agreement by joining with Japan in the Tripartite Pact, and the three countries became known as the Axis powers. The Tripartite Act was specifically designed to intimidate the United States into remaining neutral in the Sino-Japanese War and the war in Europe.