1990 World History Lech Walesa (1943– ) Archive Photos Hubble Space Telescope NASA 1990 World Wide Web debuts, popularizes Internet. Gen. Manuel Noriegasurrenders in Panama(Jan. 3). YugoslavCommunists end 45-year monopoly of power(Jan. 22). Soviet Communistsrelinquish sole power(Feb. 7). South Africafrees Nelson Mandela, imprisoned 271/2 years(Feb. 11). Violeta Barrios de Chamorroinaugurated as Nicaraguan president. Hubble Space Telescopelaunched(April 25).U.S.-Soviet summit reaches accord on armaments(June 1).Western Alliance ends cold warand proposes joint action with Soviet Union and Eastern Europe(July 6).U.S. Appeals Court overturns Oliver North's Iran-Contraconviction(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 Germanyreunited(Oct. 3).Republicans set back in midterm elections(Nov. 8). Gorbachevassumes emergency powers(Nov. 17).Leaders of 34 nations in Europe and North America proclaim a united Europe(Nov. 21).Margaret Thatcherresigns as British prime minister(Nov. 22); John Majorsucceeds her(Nov. 28).Lech Walesawins Poland's runoff presidential election(Dec. 9). Haitielects leftist priest as president in first democratic election(Dec. 17).