For the Anna Lindh Professor of Global Leadership at Harvard, it is the task of the UN, not the US, to save the world. Like many liberal academics, she exhibits "Stockholm syndrome" - identifying with the attitudes of America's enemies rather than those of most ordinary Americans.

There are two camps within the Obama administration on foreign policy. One emphasises continuity, the other change. The former is led by Hillary Clinton, the latter by the president. Robert Gates at the Pentagon and Admiral James Jones at the NSC are, like Clinton, unlikely to abandon the essentials of the Bush Doctrine: the military strategy of pre-emption (such as against Iran, which Hillary threatened to "totally obliterate" if it attacked Israel with nuclear weapons) and the political strategy of spreading democracy as an antidote to totalitarian ideologies, including Islamism.

But the president is not ready to hand over foreign policy entirely to the continuity camp. Indeed, it is widely believed in Washington that Obama has installed Power at the NSC partly to keep Hillary in check. In her capacity as senior director for multilateral affairs, Power is expected to travel frequently with the Secretary of State. Obama has effectively appointed Power to be Hillary Clinton's minder - her stooge of state.

What would one not give to be a fly on the wall when these two women meet? Hillary did not have long to savour her re-emergence as Secretary of State before realising that her every step would be dogged by a person who clearly despises her.

Moreover, Power brings her visceral hostility to Israel into the Obama White House. Walt and Mearsheimer may soon be as welcome there as Bernard Lewis was under Bush. Will Obama's Chief of Staff, Rahm Emanuel, take this lying down? The overrating of Samantha Power threatens the unity of the Obama administration.