The Yom Kippur War triggered a U.S.–Soviet crisis when the first ceasefire failed and Israeli forces encircled Egypt’s Third Army. On October 24, Soviet leader Leonid Brezhnev wrote to President Richard Nixon proposing that the superpowers act together to ensure the ceasefire, while warning that Moscow might act unilaterally if Washington did not join. The United States raised its worldwide military readiness to DEFCON 3 during the night of October 24–25.
Why Washington raised the alert
Washington saw a risk that Soviet forces could enter the conflict as fighting continued around the Third Army. Brezhnev’s message concerned enforcing the UN ceasefire; describing it solely as a plan to “save” the encircled army misses the broader diplomatic issue. U.S. officials treated the possibility of unilateral Soviet action as serious and used the alert to signal resolve while pressing Israel to stop advancing.
DEFCON 3 was a heightened military readiness level, not a decision to launch nuclear weapons. U.S. records show that the alert applied worldwide and followed a late-night meeting of senior national security officials. The State Department’s Foreign Relations record preserves the October 24 exchanges; the CIA account of the crisis describes the October 24–25 DEFCON decision and its context.
What Resolution 338 required
The Security Council adopted Resolution 338 on October 22, 1973. Its three operative clauses called on the parties to stop firing and end military activity within 12 hours; called for immediate implementation of Resolution 242; and decided that negotiations should start immediately and concurrently with the ceasefire under appropriate auspices. The text does not use the phrase “direct negotiations” or create a separate enforcement mechanism.
Fighting continued after the initial ceasefire, prompting Resolution 339 on October 23 and renewed pressure from Washington and Moscow. By October 24, a more stable ceasefire ended the war. Resolution 338 connected cessation of hostilities to implementing Resolution 242 and negotiations, while the superpower alert showed how quickly the battlefield crisis could involve the United States and Soviet Union. Read the full text of Security Council Resolution 338 and the National Security Archive’s document collection on the October War.