January 20: Republican George H. W. Bush, then known publicly as "George Bush" before the ascendancy of his son George W. Bush a decade after the first Bush presidency, is inaugurated as the forty-first president of the United States, following Republican Ronald Reagan and preceding Democrat Bill Clinton. Professional doofus Dan Quayle is his vice president. GHWB serves only a single term before his defeat in the 1993 presidential election.
February 14: Iranian dictator/popular ruler Ayatollah Ruholla Khomeini issues an Islamic fatwa against author Salman Rushdie, who wrote The Satanic Verses the previous year, which was apparently quite offensive to Muslims.
February 15: The USSR, under Mikhail Gorbachev, orders the last of its troops out of Afghanistan and the Eastern European bloc countries. Also, Boris Yeltsin is elected president, and Gorbachev is named Chairman of the Supreme Soviet.
March: Cold fusion is allegedly produced by Stanley Pons and Martin Fleischmann, both scientists at the University of Utah. The scientific community puzzles over it for a while and eventually debunks it.
March 24: The Exxon Valdez, a crude oil tanker, runs aground in Prince William Sound when the ship's drunken captain, Joseph Hazelwood, becomes unable to maneuver the large ship through a charted reef, spilling over 100 million gallons of crude oil into the environment up to and probably exceeding 100 miles away. You know what they say about long sea voyages—rum, sodomy and the lash—which were evidently in play here, in one form or another.
April 15: The Hillsborough disaster, a football stadium fire, occurs during a FIFA qualifying match in Sheffield, England, leaving dozens dead from smoke inhalation, being crushed and/or falling in the stampede to escape the massive inferno. This event lead to the modernization of outdoor sporting venues. Hillsborough Stadium had been made mostly of wood and was destroyed by fire, prompting future stadium construction to use mostly metals and composite materiel.
June 4: Peaceful protests against communism in China are met with brutal government suppression, leading to the Tiananmen Square Massacre. Images of the massacre spread around the world in print and on television, and the image of a lone Chinese student, Wang Weilin (however, the name of the man has not been verified and no one has seen him in public again), standing in the way of a battery of military tanks becomes an international symbol for the struggle for peace. Wang either faded back into anonymity or was executed for his dissent by the government of China at some later date.
June 30: The National Islamic Front instigates a coup and takes control of Sudan.
July: Hungary opens its border with Austria, producing a mass exodus of citizens out of communist Hungary. Hungary goes on to ditch communism permanently, and becomes a constitutional republic, as well as a member of the European Union, the Republic of Hungary.
September: P.W. Botha, South African president, is forced to abandon his post after suffering a stroke seven months earlier. His successor, F.W. de Klerk, promptly freed Nelson Mandela from prison, and together with Mandela the following February, the two brought about the end of Apartheid in South Africa, holding the first official elections that weren't based on race in 1994.
October 18: The Loma Prieta earthquake strikes the San Francisco bay area. The Richter Scale registers 7.1 at the height of the quake and an estimated $40 billion is required for the cleanup.
November: Mystery Science Theater 3000 makes its national debut on the Comedy Channel.
November 9: The Berlin Wall, which had divided Germany into two seperate countries (one capitalist, one communist) since 1961, falls. The depressed Soviet bloc country of East Germany is wholly assimilated into West Germany, and Germany is whole for the first time since it was divided amongst the World War II allies in 1949.
December: The Republic of Slovenia declares itself independent from Yugoslavia. Independence is finally achieved in 1991.
December 20: The United States Drug Enforcement Agency, along with several branches of the armed forces, invades Panama (in which they have no jurisdiction), obsessively bent on capturing dictator Manuel Noriega, which they do on January 3, 1990. Noriega, who was put in power by the CIA and had been on their payroll since 1966, is convicted of countless drug charges (which were not committed within the US border) and sentenced to 40 years in a US prison, where he remained until his death in 2017. Apparently the whole issue was that the US government didn't appreciate his growing power in Panama, or his growing hubris in the face of his CIA handlers.
December 25: The recently deposed Romanian president Nicolae Ceaușescu and his wife Elena Ceaușescu are executed by firing squad after a dubiously legal trial at which both were sentenced to death.
Nintendo releases the first incarnation of the Game Boy handheld console, which would go on to become the best-selling console ever (and also set the handheld gaming industry back a couple of years by not upgrading the original Game Boy until the mid-90s).
Please let me know of any other major sports results from 1989, particularly for European sports, as I am chiefly aware of only North American sports, due largely to their ubiquity where I live.