BARACK OBAMA and John McCain have spent much of the past year quarrelling about when and how the United States should leave Iraq, hoping to sway the minds of millions of American voters.

• 去年，奥巴马和卖凯恩一直就美国何时，如何撤出伊拉克这一问题争论不休，希望以此影响数百万美国选民的观点。