On 7–8 December 1941, the Japanese attack on Pearl Harbor was followed by their invasion of Malaya and, on the 8th, Churchill declared war on Japan. Three days later came the joint declaration of war by Germany and Italy against the United States. Churchill went to Washington later in the month to meet Roosevelt for the first Washington Conference (codename "Arcadia"). This was important for "Europe First", the decision to prioritise victory in Europe over victory in the Pacific, taken by Roosevelt while Churchill was still in mid-Atlantic. The Americans agreed with Churchill that Hitler was the main enemy and that the defeat of Germany was key to Allied success. It was also agreed that the first joint Anglo-American strike would be Operation Torch, the invasion of French North Africa (i.e., Algeria and Morocco). Originally planned for the spring of 1942, it was finally launched in November 1942 when the crucial Second Battle of El Alamein was already underway.