This article follows the last 72 hours of the October 1973 Yom Kippur War; that is, the three days from the collapse of the first ceasefire, on 23 October, until 25 October, when the United Nations Security Council Resolution 340, which ended the war, was adopted. The goal is to present and analyse the interests of the United States and how it managed its policy vis-à-vis Israel and Egypt during the ceasefire imbroglio. However, the article devotes special attention to the serious crisis with the Soviet Union that played out during those fateful hours. It stemmed from the note sent by the leader of the Soviet Union, Leonid I. Brezhnev, to US President Richard M. Nixon on 24 October. From the contents of the message, senior American decision-makers concluded that the Soviets were planning the unilateral deployment of an armed force to the Middle East. In response to this threat, these officials decided to raise the state of alert of the American armed forces to Level 3. The main conclusion of the research, however, is that no real Soviet threat existed. On the contrary, the Soviet Union was interested in preserving détente and in continuing to cooperate with the United States in order to put an end to the violence in the Middle East.