As president, however, either man would need to work hard to reinvigorate America's alliances.
The departure of the deeply unpopular President Bush will prompt a global sigh of relief. But it will also throw light on a fundamental disconnect between the United States and many of its allies.
Many Americans believe that once Mr. Bush is gone, allies will step forward and share the burdens of leadership. Many allies believe that once Bush is gone, Washington will start listening to them more.
Since the collapse of the Soviet Union, allies' fears of an existential threat have declined, along with their willingness to share risks and costs with their American partner.
Washington remains the only capital able to run a global foreign policy and to project military power anywhere on earth. But America's recent sorrows, including the wrong-headed misadventure in Iraq and the financial crisis, only make it harder for it to demand loyalty and sacrifice from others.