Era · 1945 – present
From the Cold War and the Space Race to the fall of the Berlin Wall and the world we live in today.
Volcanic mudflows killed about 23,000 people, more than 20,000 of them in Armero, making it the deadliest volcanic disaster since 1902 and a lesson in the failure of hazard warnings.
Hundreds of buildings collapsed in Mexico City; estimates of deaths range from about 5,000 to more than 10,000, and the disaster led to new building codes, a civil protection system and a seismic alert network.
The discovery of springtime ozone loss over Antarctica confirmed the danger of chlorofluorocarbons and led to the Montreal Protocol of 1987, which phased out ozone-depleting chemicals worldwide.
The summit ended without an agreement because of disagreement over the Strategic Defense Initiative, but its proposals paved the way for the INF Treaty of 1987 and later strategic arms cuts.
Ferdinand Marcos fled into exile on 25 February 1986 and Corazon Aquino became president, ending two decades of Marcos rule.
Mir hosted crews for most of 15 years, set endurance records still partly unbeaten and, through Shuttle-Mir, laid the groundwork for the International Space Station before being deorbited into the South Pacific.
All seven crew members died; the shuttle fleet was grounded for 32 months while the solid rocket boosters were redesigned and NASA's management was reformed.
The twelve European Community members committed to completing a single market by the end of 1992 and reformed the Community's decision-making.
Reactor No. 4 exploded and burned, spreading radioactive contamination across Europe; hundreds of thousands of people were resettled and a large exclusion zone remains.
Militarily inconclusive: the Angolan offensive was defeated, but South African attacks on Cuito Cuanavale failed, and the stalemate led to the 1988 New York Accords.
The United States and the Soviet Union destroyed 2,692 missiles by June 1991, eliminating an entire class of nuclear weapons under on-site inspection.
The speech drew limited attention at the time but became one of the best-known addresses of the Cold War after the Berlin Wall fell in November 1989.
