There is an old principle that you shouldn't hire someone you can't fire. That is why Barack Obama would make a huge mistake if he were to pick Hillary Clinton as his Secretary of State.

It's not that the choice would be terrible for US foreign policy. She would surely do an excellent job - thorough, detailed, tenacious - as she has in her eight years as senator for New York. But it would hand the rebuilding of America's worldwide reputation - one of the defining themes of Mr Obama's campaign and presidency - to someone who has her own strong views. Not disastrous views, at all, from what we know. But different from his; sometimes subtly, sometimes sharply, and very definitely hers.

It has taken two weeks since Mr Obama's victory for the Hillary problem to boil to the surface. In that time Democratic Washington has slid from euphoria into hyperanxiety, as people jostle for the 8,000 administration jobs (and that's before counting the Democratic jobs on Capitol Hill). The Washington Post, which devotes a couple of pages a day to speculation on who's up and who's down, noted on Thursday, under the headline “Grab a Chair”, that a huge reshuffle of Senate committee chairmanships looked like leaving Mrs Clinton with nothing. “Nada? Zip?” it asked, despite her seniority and the efforts she made (eventually) to help Mr Obama to defeat John McCain.

In the past five days, she has shot to the top of the list for Mr Obama's foreign policy supremo, rivalling Senator John Kerry, the failed 2004 presidential candidate, and Bill Richardson, Governor of New Mexico and primary contender. Better in the tent than out, seems to be the Obama team's thinking.

Up to a point. Yes, she could do some damage if spurned. When Mr Obama talks about bipartisanship, that means not just reaching over to Republicans but to Democrats alienated by the bitter primaries. Those include women of Mrs Clinton's generation, and her assertive brand of feminism, who felt that her race meant their time had come.

Even more important may be the white working-class voters who backed her. To the end, Mr Obama never won their support. But to survive the ferocious battles of this recession, he will need all Democrats in Congress on his side. He may have to reach over their heads, too, and call on popular support for tough measures in tough times. He will need those who wanted Mrs Clinton.

It is true, too, that she knows a lot about foreign policy. Her worst campaign mistake trail was to claim that she had arrived in Bosnia under gunfire (and not to realise that footage of the cheerful welcoming committee inevitably existed). But to give her credit, she has pitched up in a lot of troublespots.

I saw her at her best in the Senate Armed Services Committee two years ago. The senators, grilling General John Abizaid, then head of Central Command, about Iraq, struggled to stick to their allotted six minutes, and to pose questions, not make speeches. Mr McCain was the worst, jabbing at the ceiling and breaking into a shout at unseen enemies, a disturbing spectacle in the quiet room. Not Mrs Clinton. She took the general to task for all but contradicting himself in his desire to assent to every option. You'd be delighted to have her as a lawyer.

So she would do the US proud as Secretary of State. But she wouldn't help Mr Obama as president. She wouldn't flatter him; she wouldn't really defer to him; she might challenge him, even though she couldn't actually upstage him.

The rapturous reception that Mr Obama has received in much of the world is based on his promise of change. He says that he is the face of a new America; does he really want to be represented by one of the most familiar faces of the past? Or by anyone who will compete with him (and eclipse Joe Biden, the Vice-President and a foreign affairs specialist)? Foreign policy these days is an intimate affair, carried out between leaders, on the phone, or in faux-friendly fishing trips. The Secretary of State role has become more technical, less independent. Ask Condoleezza Rice. Or David Miliband.

Would Mrs Clinton be happy to play that role? Surely not. It is inevitable that she would disagree with Mr Obama, on substance as well as style. After all (as he endlessly reminded voters), she backed Iraq at the start, where he opposed it. She will have her own views on the decisions of her husband's presidency (the Middle East, Balkans, North Korea), many well judged, but messy in their legacy. Come to that, Bill will have even stronger views.

On that note, her husband's complicated hinterland could bring its own problems. Mr Obama's team is now said to be asking about conflicts of interest that his connections might now cause her. If they exist, wouldn't they have also been a problem for her as president? Sure, but he might have more incentive to simplify them brutally if she were in the White House, than if she were merely Secretary of State.

Mr Obama can't really afford to offer Hillary the prize of Secretary of State. Yet for her (and her husband), it is a long way short of the prize she so recently thought she would get. She will resent Mr Obama. And he won't be able to get rid of her.

奥巴马应该抵挡住任命希拉里作国务卿的诱惑。一旦希拉里成了国务卿，奥巴马就永远无法解雇她。

职场中有一条古老的原则：你决不能任用一个你解雇不了的人。这就是为什么对于奥巴马来说，任命希拉里做国务卿将是一个巨大的错误。

并不是说希拉里做国务卿将不利于美国外交。毫无疑问，希拉里会做得很好——就像她八年来作为纽约州参议员所表现出来的：工作彻底、细致、不屈不挠。但是任命希拉里将奥巴马竞选活动和总统任期的中心问题——重建美国在全球的声誉——交给一个固执己见的人。我们可以知道，希拉里的固执的不是会给美国带来灾难的观点。但这些观点与奥巴马的观点是有分歧的；这种分歧有时明显，有时尖锐，但无疑是希拉里式的。

如何安排希拉里的问题在奥巴马竞选成功之后两周终于有了一个答案。这期间，民主党人们为了新政府中的8000个职位（这还没有算上议会中民主党人的位子），从满心欢喜到焦躁不安。每天都会花几个版面猜测新政府中谁上谁下的华盛顿邮报，周四以“抢位子”为标题指出参议院委员会主席的重新洗牌会让希拉里一无所有。希拉里资历很深，又给予了奥巴马那么多支持，“难道真的什么都没有？”

过去几天里，希拉里一路窜升至新政府外交政策掌门人候选者名单的前列，与2004年失利的民主党候选人、参议员John Kerry，和今年党内初选的竞选人、新墨西哥州州长Bill Richardson平起平坐。“名单上有你总比没有好”似乎是奥巴马组阁团队的想法。

在一定程度上。没错，希拉里的失势可能带来祸患。奥巴马的两党政治，不单是指联合共和党人，更指团结那些在惨烈的初选中改变想法的民主党人。这其中也包括如希拉里这样的年纪的女性和把希拉里的竞选看作是女性时代到来的自信的女权主义者们。

更重要的也许是支持希拉里的那些白人工薪阶层选民。一直到整个选举的最后，奥巴马从来没能赢得他们的支持。但是要在这场经济衰退的危机中求生，奥巴马需要议会中全体民主党人的支持。他或许还需要民主党高层的支持，和民众对于他特殊时期特殊政策的支持。他需要那些希拉里的支持者。

的确，希拉里对外交政策很有研究。她在整个竞选过程中最大的错误就是她声称“在枪林弹雨中抵达波斯尼亚”（而且没有意识到存在着一份记录了欢迎者热烈欢迎她的影像资料）。但不可否认的是，她的确到过很多战火纷飞的地方。

两年前，我在参议院军事委员会见到了希拉里的巅峰时刻。就伊拉克问题纷纷炮轰时任中央司令部司令的John Abizaid的议员们都抓紧自己的六分钟时间提问，而不是发表演讲。反应最激烈的麦凯恩指着天花板，对着臆想中的敌人咆哮起来，这在安静的房间里是一幕令人不安的奇观。希拉里当时就不一样。她批评了那位将军的所有观点，却并没有指出对方想要接受每一种备选答案时候的自相矛盾。你一定希望有一个希拉里一样的人作你的律师。

作为国务卿，希拉里会让美国骄傲。但是他并不能给奥巴马总统以帮助。她不会奉承他；她不会顺从他；即便她没办法抢戏，她也许会挑战奥巴马的权威。

世界欣然接受奥巴马是因为他带来变革的承诺。他说他是新美国的面孔；那么他真的希望找一个再熟悉不过的就面孔做自己的代言人？或者选择一个会和自己竞争的人（更何况这个人还会抢了外交事务专家出身的副总统拜登的风头）？在这个时代，外交是一项很私人的活动；是两国领导人通过电话，或者在貌合神离的垂钓中完成的。国务卿的职位更多变成技术性的，自主性也下降了。不信的话问问赖斯或者米利班德。

希拉里会乐意扮演那样的角色么？当然不会。她与奥巴马产生分歧是不可避免的，无论是在政策实质上还是在行事方式上。毕竟，（就像奥巴马从竞选开始就不断提醒选民的）希拉里从开始就支持伊拉克战争，而他从开始就反对。她对于克林顿政府的一些政策决定（比如中东、巴尔干和朝鲜）有她自己的见解；这些政策中很多都很有道理，但却给后来政府留下了麻烦。克林顿本人在这些问题上观点会更强硬。

考虑到这一点，克林顿复杂的背景会带来它的问题。据说，奥巴马的团队现在还对比尔是否将对会对希拉里带来利益冲突存在疑问。如果这些冲突存在，即便希拉里成为总统是不是也会成问题？当然会，但如果希拉里是总统，比尔会简单地把这些问题简化；但现在希拉里只是国务卿，情况就不一样了。

对于奥巴马来说，任命希拉里做国务卿这个奖励实在代价太高了。而另一方面，对于希拉里（也包括比尔）来说，国务卿这个位置和她的预期相差太远。希拉里将怨恨奥巴马。奥巴马却摆脱不掉希拉里。