In 1942, Oppenheimer was recruited to work on the Manhattan Project, and in 1943 was appointed director of the project's Los Alamos Laboratory in New Mexico, tasked with developing the first nuclear weapons. His leadership and scientific expertise were instrumental in the project's success. On July 16, 1945, he was present at the first test of the atomic bomb, Trinity. In August 1945, the weapons were used against Japan in the bombings of Hiroshima and Nagasaki, to date the only use of nuclear weapons in an armed conflict.