Michele Flournoy resigned today as undersecretary of defense for policy. Long expected: her aides said in mid-2010 she probably wouldn’t stick around very long in the job if Obama passed her over for secretary of defense. But after she leaves in February, don’t think of Flournoy as gone. Think of her as entering a state of Pentagon chrysalis.

Defense wonks occasionally play a game about whether the 2010 Quadrennial Defense Review — think of it like a mega-strategy document that rarely bears much relationship to actual Pentagon strategy — was destined to be overtaken by events. (I know, right? I wish we could play Arkham City instead.) The document, Flournoy’s biggest tangible achievement, basically reoriented defense strategy to be about supporting the present-day war in Afghanistan and cutting away the dross of more marginal missions. It didn’t anticipate that the Pentagon was going to face big budget cuts. Nor did it anticipate that the focus of broader U.S. strategy was going to be the western Pacific by the time the document expired. Now Flournoy’s wrapping up a review about how defense strategy copes with the budget cuts. Her last major act in office is essentially to revise her major achievement.

I don’t have a strong opinion on whether the 2010 QDR was bullshit. Others do.

But I doubt that the outcome of that debate will harm her career. I spent a couple months profiling Flournoy for Washingtonian last year. What I hope that article demonstrates is that she has a major constituency for herself within the military — in the Army, the Navy and the Marines. (Couldn’t find many fans of hers in the Air Force, though; that’s not to say they’re not there.) The services see her as an empathetic ally with political heft in addition to being a respected defense theorist. These are rare qualities for someone in the Democratic orbit.

To some degree, how people come to see Flournoy will be a cipher for how they see Leon Panetta. Panetta got the job that Flournoy wanted. And he’s starting to be viewed as something of a clown. Bob Gates benefited from following the reviled Donald Rumsfeld; Panetta has the burden of being not-Gates. But Flournoy was Gates’ ally, inside and outside the Pentagon. If Panetta doesn’t have a successful tenure, she’ll be seen as the keeper of a Gates Restoration.

Of course, there may be a Republican administration in between. But she’s come through the Pentagon looking like something of an heir apparent. She’s automatically in the conversation for Next Defense Secretary with a Democratic White House.

But should she? She was a major architect of the Obama administration’s counterinsurgency strategy in Afghanistan. At the very minimum, that strategy underperformed. We’ll see what her final strategy review ultimately looks like. It couldn’t hurt for Flournoy to do some public introspection about what went wrong and why she backed something that doesn’t appear to have worked. (She would be the rare policymaker who did.) But chances are it’ll be the strength of her network that puts her in Panetta’s chair more than the strength of her ideas.