That being said, you raise an excellent point. The popular foreign policy debate in America runs something like this: either you're ready to send troops anywhere at any time to kick ass on anyone or you're less than the perfect patriot, and unfit for the presidency.
What if, given that debate, as a future White House contender she offered nothing as SecState that might jeopardize her future chances? She'd serve the country - and the world - poorly indeed.
If she's hypothetically considering a future white house run, she should decline. It is almost certain that there will be situations ahead as SecState where she'll have to make the choice: serve well, or harbor your ambitions? "It Can't Be Just About Us"--Frank Schnittger, ETian Extraordinaire
On the whole, I think she could eventually be a good, even great SecState, based just on her qualities of character. She does have some baggage coming out of the starting gates, though nothing that cannot be overcome.
As a matter of personal style, her stridency makes her the wrong face to put on US public diplomacy. That's absolutely the wrong way the US needs to go on public diplomacy in the near future. "It Can't Be Just About Us"--Frank Schnittger, ETian Extraordinaire