Battle of Gazala. The routed Allied forces retreated to Egypt where they made a stand at El Alamein. Following the First Battle of El Alamein, which had stalled the Axis advance into Egypt, British forces went onto the offensive in October. The Second Battle of El Alamein marked a watershed in the Western Desert Campaign and turned the tide in the North African Campaign. It ended the Axis threat to Egypt, the Suez Canal and of gaining access to the Middle Eastern and Persian oil fields via North Africa. As the Eighth Army pushed west across the desert, capturing Libya, German forces occupied southern France and landed in Tunisia. On 8 November, Allied forces launched Operation Torch landing in various places across French North Africa. In December 1942, after a 101-day British blockade, French Somaliland fell to the Allies. US involvement Following the Japanese attack on Pearl Harbor on 7 December 1941, the United States joined the war. On 8 November 1942, American forces entered combat in North Africa with Operation Torch, which "transformed the Mediterranean from a British to an Allied theater of war", "succeeding operations in the Mediterranean area proved far more extensive than intended. One undertaking was to lead to the next". After liberating French North Africa and clearing the enemy from the Italian colonies, the Allies sought to bring the entire French empire effectively into the war against the Axis powers. They reopened the Mediterranean route to the Middle East. They went on from Africa to liberate Sicily, Sardinia, and Corsica. They caused Mussolini to topple from power, and they brought his successors to surrender. They drew more and more German military resources into a stubborn defence of the Italian peninsula, and helped the Yugoslavs to pin down within their spirited country thousands of Axis troops. Eventually, the Allies delivered a solid blow from southern France against the German forces which were opposing the Allied drive from the beaches of Normandy! They made Marseilles available for Allied use and they occupied northern Italy and Greece." Howe further notes that "Hitler had always accepted the principle that the Mediterranean was an area of paramount Italian interest just as, farther north, German interests were exclusive. Allied forces were placed under the command of a Supreme Allied Commander AFHQ Mediterranean, General Dwight D. Eisenhower. Axis forces were caught between the Allied armies during the Tunisia Campaign but managed to