In 1947, during the U.S.–U.S.S.R. Cold War, the clock was started at seven minutes to midnight, and subsequently advanced and rewound per the state of the world and nuclear war prospects. Setting the clock is relatively arbitrary, and decided by the directors of the Bulletin of the Atomic Scientists reflecting global affairs. The clock has not always been set and reset as quickly as events occur; the closest nuclear war start, the Cuban Missile Crisis in 1962, reached crisis, climax, and resolution before it could be set to reflect that possible doomsday.