Soon after the United States entered the war, the western Allies decided that their essential military effort was to be concentrated in Europe, where the core of enemy power lay, while the Pacific theater was to be secondary.
In the spring and summer of 1942, British forces were able to break the German drive aimed at Egypt and push German General Erwin Rommel back into Libya, ending the threat to the Suez Canal, which connected the Mediterranean to the Red Sea.
On November 7, 1942, an American army landed in French North Africa, and after hard-fought battles, inflicted severe defeats on Italian and German armies. The year 1942 was also the turning point on the Eastern Front, where the Soviet Union, suffering immense losses, stopped the Nazi invasion at the gates of Leningrad and Moscow, and defeated the German forces at Stalingrad.
In July 1943 British and American forces invaded Sicily, and by late summer the southern shore of the Mediterranean was cleared of Fascist forces. Allied forces landed on the Italian mainland, and although the Italian government accepted unconditional surrender, fighting against Nazi forces in Italy was bitter and protracted. Rome was not liberated until June 4, 1944. While battles were still raging in Italy, Allied forces made devastating air raids on German railroads, factories and weapon emplacements, including German oil supplies at Ploesti in Romania.
Late in 1943 the Allies, after much debate over strategy, decided to open a Western front to force the Germans to divert far larger forces from the Russian front. U.S. General Dwight D. Eisenhower was appointed Supreme Commander of Allied Forces in Europe. After immense preparations, on June 6, 1944, the first contingents of a U.S., British and Canadian invasion army, protected by a greatly superior air force, landed on the beaches of Normandy in northern France. With the beachhead established after heavy fighting, more troops poured in, and many contingents of German defenders were caught in pockets by pincer movements. The Allied armies began to move across France toward Germany. On August 25 Paris was liberated. At the borders of Germany, the Allies were delayed by stubborn counteraction, but by February and March 1945, troops advanced into Germany from the west, and German armies fell before the Russians in the east. On May 8 all that remained of the Third Reich surrendered its land, sea and air forces.