United States President George H.W. Bush poses for photographers after delivering an address to the nation from the Oval Office of the White House in Washington, DC on Christmas Day, December 25, 1991 announcing the resignation of President Mikhail Gorbachev as President of the Union of Soviet Socialist Republics, marking the collapse of the Soviet Union and the end of the Cold War. Photo by Arnie Sachs / CNP /ABACAPRESSC.OM