The Second World War made the US a superpower. As the international situation deteriorated, Roosevelt began supporting the Allies via Lend-Lease and rearming the US, particularly via navy bills, and made the US the “arsenal of democracy.” Hitler’s Nazi Germany, Mussolini’s Italy, and Tojo’s Japan formed the Tripartite Axis alliance. Roosevelt and Britain’s Winston Churchill agreed they would seek the defeat of the Axis, pursuing a “Germany First” offensive strategy while fighting defensively in the Pacific. The Allies argued over when and where to launch a Second Front and struggled to prepare the troops and material needed for this. The US and Great Britain defeated Germany’s U-boat campaign and launched a combined bomber offensive against Germany. The US and Britain fought in North Africa, then forced Italy from the war, and invaded Normandy, France, in Operation OVERLORD in June 1944. Germany surrendered in May 1945. In June 1942, the US won the pivotal Battle of Midway against Japan. The US then went on the offensive at Guadalcanal in the Solomon Islands. The US launched history’s most successful submarine guerre de course against Japan, while mounting a two-pronged Pacific offensive and seeking to destroy the Japanese Navy. The offensives met at the Philippines, and then leapt to Iwo Jima and Okinawa. The dropping of the atomic bombs pushed Japan to surrender. The “Big Three” settled the postwar situation at Yalta and Potsdam.