At noon on Jan 20, George W. Bush hands successor Barack Obama two unfinished wars and a worldwide economic meltdown and leaves historians the job of judging his tumultuous eight-year presidency.

The 43rd US president also bequeaths the controversial global "war on terror" that he credits for protecting the United States after the September 11, 2001 attack - the worst strike ever on US soil.

Bush, 62, will also leave behind a Middle East still in flames, uneasy relations with Russia, and, his supporters say, vastly improved ties with Brazil, China, and India.