World Wide Web debuts, popularizes Internet. Gen. Manuel Noriega surrenders in Panama(Jan. 3).Yugoslav Communists end 45-year monopoly of power (Jan. 22).Soviet Communists relinquish sole power (Feb. 7).South Africa frees Nelson Mandela, imprisoned 271/2 years (Feb. 11).Violeta Barrios de Chamorro inaugurated as Nicaraguan president. Hubble Space Telescope launched (April 25). U.S.-Soviet summit reaches accord on armaments (June 1). Western Alliance ends cold war and proposes joint action with Soviet Union and Eastern Europe (July 6). U.S. Appeals Court overturns Oliver North's Iran-Contra conviction (July 20). Iraqi troops invade Kuwait and seize petroleum reserves, setting off Persian Gulf War (For detailed chronology, see The Persian Gulf War.) (Aug. 2et seq.). East and West Germany reunited (Oct. 3). Republicans set back in midterm elections (Nov. 8).Gorbachev assumes emergency powers (Nov. 17). Leaders of 34 nations in Europe and North America proclaim a united Europe (Nov. 21). Margaret Thatcher resigns as British prime minister (Nov. 22);John Major succeeds her (Nov. 28). Lech Walesa wins Poland's runoff presidential election (Dec. 9).Haiti elects leftist priest as president in first democratic election (Dec. 17).