The First Washington Conference, also known as the Arcadia Conference (ARCADIA was the code name used for the conference), was held in Washington, D.C., from December 22, 1941, to January 14, 1942.
On 7/8 December 1941, Japan invaded Thailand and attacked the British colonies of Malaya, Singapore, and Hong Kong as well as the United States military and naval bases in Hawaii, Wake Island, Guam, and the Philippines.
On 8 December, the United Kingdom,[a] the United States,[b] Canada, and the Netherlands declared war on Japan, followed by China and Australia the next day. Four days after Pearl Harbor, Germany and Italy declared war on the United States, drawing the country into a two-theater war.
The conference brought together the top British and American military leaders, as well as Winston Churchill and Franklin Roosevelt and their aides, in Washington from December 22, 1941, to January 14, 1942, and led to a series of major decisions that shaped the war effort in 1942–1943.
Arcadia was the first meeting on military strategy between Britain and the United States; it came two weeks after the American entry into World War II. The Arcadia Conference was a secret agreement unlike the much wider postwar plans given to the public as the Atlantic Charter, agreed between Churchill and Roosevelt in August 1941.
The main policy achievements of Arcadia included the decision for "Germany First" (or "Europe first"—that is, the defeat of Germany was the highest priority); the establishment of the Combined Chiefs of Staff, based in Washington, for approving the military decisions of both the US and Britain; the principle of unity of command of each theater under a supreme commander; drawing up measures to keep China in the war; limiting the reinforcements to be sent to the Pacific; and setting up a system for coordinating shipping. All the decisions were secret, except the conference drafted the Declaration by United Nations, which committed the Allies to make no separate peace with the enemy, and to employ full resources until victory.
In immediate tactical terms, the decisions at Arcadia included an invasion of North Africa in 1942, sending American bombers to bases in England, and for the British to strengthen their forces in the Pacific. Arcadia created a unified American-British-Dutch-Australian Command (ABDA) in the Far East; the ABDA fared poorly. It was also agreed at the conference to combine military resources under one command in the European Theater of Operations (ETO).