Before the first Israeli nuclear bomb was ready in 1967, on the eve of the Six-Day War, the Soviet Union, which was primarily concerned with preventing an Israeli bomb, and the Arab states had allied themselves. However, no one had expected the success of the Israeli preemptive attack on the Arab air force, so that the Soviet Union ultimately remained passive in the war. Then, in 1969, a secret agreement had been reached between Golda Meir and Richard Nixon in which the United States allowed Israel to be a nuclear power.