WHEN President George W Bush invoked the memory of Vietnam to justify staying in Iraq, he was drawing on a new wave of revisionist history which maintains that America did not lose the war, but the will to win. “Three decades later there is a legitimate debate about how we got into the Vietnam war and how we left,” Bush said in a speech to army veterans last week. White House insiders admitted it was a risky topic which had previously been left to the antiwar movement. Americans generally prefer to forget Indochina and remember who won the cold war....