As World War II approached science, especially regarding electronics, aerospace research and nuclear physics became very important. Equally important was keeping new developments in these areas secret. The first new scientific breakthrough was the British development on a radio detection system that helped defeat the Luftwaffe in the Battle of Britain. The U.S. took the basic British research amd developed highly effective radar systems which were instrumental in defeating the German U-Boat threat in the Atlantic. The development of the a proximity fuse for anti-air and Navy guided artillery were major factors in the Allies victory. The most secret, and ultimately most advanced scientific achievement of the wear, was the development of the atomic bomb. The Manhattan Project developed the atomic bomb with the first test in July 1945. Two a Bombs were dropped on Japan in August and the Japanese surrounded on September 2nd ending World War II. Post wat, military R&D became a priority and the scientific breakthroughs have become as much a part of modern war as strategy and tactics.