The phrase was coined by British prime minister Winston Churchill (1874-1965). It refers to the situation during the Cold War, when both the United States and the Soviet Union had the capacity to destroy each other with nuclear weapons. In the event of war, the destruction on both sides would have been so huge that neither side was prepared to risk starting such a conflict. A balance of terror existed. The doctrine of MAD (Mutual Assured Destruction) was a later variant of the idea of the balance of terror.