One day after the attack on Pearl Harbor, the Japanese carried out an air strike on the Philippines, again catching the US air force unprepared. The Japanese soon occupied much of the island nation, driving US troops under General Douglas MacArthur onto the Bataan Peninsula. MacArthur himself left by submarine to Australia, promising “I shall return.” But on April 8, 1942, Japanese troops captured the cornered Americans and Filipinos, later extending their reach (May 6) to the last holdouts on the small island of Corregidor. From there the captives were forced into a grim “death march” toward Japanese prison camps; most of the tens of thousands of men died before they reached the camps. Around this same time (May 7–8), the Allies headed off a Japanese invasion of southern New Guinea (a precursor to the invasion of Australia) at the Battle of Coral Sea.

One day after the attack on Pearl Harbor, the Japanese carried out an air strike on the Philippines, again catching the US air force unprepared. The Japanese soon occupied much of the island nation, driving US troops under General Douglas MacArthur onto the Bataan Peninsula. MacArthur himself left by submarine to Australia, promising “I shall return.” But on April 8, 1942, Japanese troops captured the cornered Americans and Filipinos, later extending their reach (May 6) to the last holdouts on the small island of Corregidor. From there the captives were forced into a grim “death march” toward Japanese prison camps; most of the tens of thousands of men died before they reached the camps. Around this same time (May 7–8), the Allies headed off a Japanese invasion of southern New Guinea (a precursor to the invasion of Australia) at the Battle of Coral Sea.

After the important US naval victory at the Battle of Midway (June 1942), American forces steadily advanced up the chain of Pacific islands toward Japan. Meanwhile, the ongoing Battle of the Atlantic continued, with Allied ships and German submarines playing a deadly game of cat and mouse. Likewise, on the Continent a great air war against Germany was taking place (1942–44). The British led a North African campaign against Italian and German forces, ending with the latter’s defeat there in 1943. Allied troops then invaded Sicily and Italy, delivering a defeat to the Fascist government (July 1943). In Russia, the Germans were stonewalled at the Battle of Stalingrad (1943) and eventually pushed out of the region by Soviet forces. The large-scale Allied invasion of Western Europe started with Operation Overlord, the codename for the great Normandy Campaign (1944) in western France. After succeeding against the Germans there, Allies pushed toward Germany itself, winning the dreaded Battle of the Bulge (December 1944-January 1945) among other confrontations. In March 1945 a massive assemblage of Allied troops crossed the border into Germany; they were subsequently met from the east by Soviet forces. V-E Day (Victory-in-Europe Day) was announced with the surrender of Germany on May 8, 1945.

In the Pacific, the Allies, led by the United States (under General MacArthur), invaded the Philippines in 1944 and backed up the effort through the Battle of Leyte Gulf and the costly battles of Iwo Jima and Okinawa (1945). With the dropping of US atomic bombs on the Japanese cities of Hiroshima and Nagasaki (August 1945), the war abruptly ended. V-J Day (Victory-in-Japan Day) occurred with Japan’s formal surrender on September 2, 1945.