How Close the Human Race Came to Ending Life on Earth Every Year Since 1947

A break in the Cold War takes place in Glassboro, New Jersey, when President Lyndon Johnson and Soviet Premier Alexei Kosygin meet to discuss relations between the two countries.

Across the globe, regional wars rage, and U.S. involvement in Vietnam intensifies. Tensions flare between North Korea and the U.S. after the communist state captures the USS Pueblo. Johnson declines to run again for president, and the Soviet Army crushes a revolt in Czechoslovakia. As it moves the clock forward, closer to midnight, the Bulletin laments, “There is a mass revulsion against war, yes; but no sign of conscious intellectual leadership in a rebellion against the deadly heritage of international anarchy.”

The Cold War takes a backseat to a human achievement. In July, Apollo II lands on the moon, a major accomplishment in the space race. The Bulletin again moves the clock back from midnight, from seven to 10 minutes to midnight.

The Treaty on the Non-Proliferation of Nuclear Weapons goes into effect.

The U.N. General Assembly officially recognizes the People’s Republic of China as a legitimate governing body.

The Bulletin of Atomic Scientists moves the clock two minutes back from midnight, explaining: “The United States and Soviet Union attempt to curb the race for nuclear superiority by signing the Strategic Arms Limitation Treaty (SALT) and the Anti-Ballistic Missile (ABM) Treaty. The two treaties force a nuclear parity of sorts.”

This year, the U.S. officially exits the war in Vietnam, marked with the signing of the Paris Peace Accords.

The clock moves closer to midnight for the first time since 1968. The Bulletin of Atomic Scientists explains: “South Asia gets the Bomb, as India tests its first nuclear device. And any gains in previous arms control agreements seem like a mirage. The United States and Soviet Union appear to be modernizing their nuclear forces, not reducing them.”

The Fall of Saigon officially ends the Vietnam War as North Vietnamese forces take over the capital city of South Vietnam.

Chinese leader Mao Zedong dies. He served as chairman or chief of state of the People’s Republic of China from 1949 to 1959 and chairman of the party until his death.