It’s no secret that Barack Obama wants to close the terrorist detention facility at Guantanamo Bay, although his zeal for the project has often been questioned. Obama’s first action as President consisted of a directive to close the prison, but almost six years later, it’s still in operation — and relatively popular, at least in contrast with the alternatives. Obama has embarked on a strategy to close Gitmo through default by emptying it of its detainees, but there has been one impediment to that strategy. Congress requires the Secretary of Defense to attest that any released detainees pose no threat to the security of the United States, or that any threat could be neutralized.

Unfortunately for Obama, Chuck Hagel took that responsibility a little too seriously, and Politico’s Glenn Thrush reports that it was one of the big issues in his firing:

However, current and former officials said the White House’s frustration with Hagel was not limited to the fight against the Islamic State. In the eyes of Obama aides, Hagel could be maddeningly slow to respond to policy directives from the White House. When Obama began pushing last year to reinvigorate the process of closing the Guantanamo detention camp, White House aides repeatedly urged Hagel to sign off on transfers of detainees who had long been cleared for release. Yet for months, the defense secretary refused to sign certifications that the future threat posed by the prisoners could be adequately mitigated, according to a U.S. official. “This was not an insignificant source of friction,” said the official, who asked not to be named. “I can say definitively on this one it has been utterly public and unmistakeable in terms of the disconnect.”

White House irritation with Hagel grew so intense that last May, Rice sent Hagel an extraordinary memo directing him to report every two weeks on progress toward transferring or releasing Guantanamo prisoners, the source said, discussing a directive first reported earlier this year by the New York Times. “He was the bottleneck,” said one advocate closely tracking the process. “He wasn’t signing off.” There was little movement from Hagel until a meeting of national security principals last month, which pushed the defense secretary to reluctantly approve a few transfers, the official said. While few analysts believe the tug-of-war over Guantanamo releases was a key factor in Hagel’s departure, it was a piece of the broader problems in his relationship with the White House. “There were several things, but this was certainly a weight on the scale that actually registered,” the official said.

Hagel signed off on the most controversial release — the trade of five high-ranking Taliban commanders for Bowe Berghdahl. In fact, in what retrospectively looks like a stunning act of hypocrisy, the White House pushed all of the blame for that release onto Hagel’s shoulders when the political fallout got too strong for Obama to handle. House Armed Services chair Buck McKeon scoffed at the blameshifting. “It was the president of the United States that came out [in the Rose Garden] with the Bergdahls and took all the credit,” McKeon said, “and now that there’s been a little pushback he’s moving away from it and it’s Secretary Hagel?”

Clearly that wasn’t the case. Now that Hagel has been fired — and no one’s seriously disputing that characterization — the White House now wants to blame Hagel for not being freer with the rubber stamp. In fact, it was just a month after the Obama administration left Hagel twisting in the wind that six more Gitmo detainees got freed. Some bottleneck.

What happens from here? Obama wants a wartime consigliere now that his withdrawal strategies have failed, and Ted Cruz has just the right guy for the job:

Sen. Ted Cruz (R-Texas) has offered President Obama some unsolicited advice on who to pick to replace outgoing Defense Secretary Chuck Hagel.

Cruz, who in two years would like Obama’s job, decided former senator Joe Lieberman, the Democrat turned Independent from Connecticut, would be a perfect choice.

“One strong option would be former Senator Joe Lieberman, a member of the President’s own party with deep experience and unshakable commitment to the security of the United States. I urge the President to give him full and fair consideration for this critical position,” Cruz said in a press release.

Lieberman would actually make a pretty good SecDef, in part because he sees national security issues a lot more clearly than Barack Obama. That was why Lieberman broke ranks and endorsed John McCain in 2008, and refused to endorse Obama in 2012 (he stayed neutral).  For those reasons alone, Obama won’t pick Lieberman unless he’s really desperate to fill the slot, especially since Obama’s grassroots base ran Lieberman out of the Democratic Party in 2006 for those views, and Obama can’t afford to alienate the one constituency he has left. There are other reasons we won’t see a political pick for SecDef — and probably not for most appointments in the lame-duck era, as I explain in my column for The Week:

The Washington Post’s Dana Milbank accused Obama of turning into George W. Bush for cashiering the “man of peace” from his post at Defense. Milbank lamented the way that “the neo-cons who dominated the Bush administration feel some vindication” from Obama’s change of direction. At the other end of the spectrum, Sen. Ted Cruz publicly endorsed Joe Lieberman, a passionate defender of the Iraq and Afghanistan wars, as Hagel’s replacement.

Obama cannot afford to tip his hand that blatantly, though, to keep the damage on his left to a minimum. The only real path open to Obama at this point, for an aggressive policy of engagement, will be to select a technocrat with plenty of experience at Defense while not having the political clout to challenge Obama’s policies.

Michele Flournoy, who served under Gates and Panetta as a deputy secretary, would make the most sense politically for Obama, giving him an opportunity to make history by appointing a woman and possibly muting progressive criticism on national security policy. However, theAssociated Press reported that Flournoy wants more control over defense policy than Hagel was allowed. If Flournoy doesn’t get the nod, former deputy defense secretary Ashton Carter or his successor Robert Work are getting mention as potential short-list choices. None of these would likely provoke Republican opposition, and would probably handle a confirmation hearing better than Hagel did.

The technocrat model may be the answer for the lame-duck period of the Obama presidency in other areas, too. Technocrats make difficult targets, even in a hostile environment. Senate Republicans are not likely to block confirmations on national-security positions, but after Obama’s unilateral declaration on immigration, they will target other appointments from Obama in response to his bypassing of Congress.

If it is Michele Flournoy, though, she might have to explain this 2012 ad for Obama in a confirmation hearing:

In retrospect, Romney looks a lot smarter than Obama or Flournoy.

Update: Maybe that’s why Flournoy’s out:

Michèle Flournoy, the most-widely rumored candidate to replace Chuck Hagel as the next secretary of defense, has taken herself out of the running for the job, according to sources familiar with the situation. The decision complicates what will be one of the most important personnel decisions of President Barack Obama’s second term.

Flournoy, the co-founder and CEO of the Center for a New American Security, a think tank that has served as a farm league for future Obama administration officials, would have been the first female secretary of defense had she risen to the position.

But in a letter Tuesday to members of the CNAS board of directors, Flournoy said she would remain in her post at the think tank and asked Obama to take her out of consideration to be the next secretary of defense. Flournoy told the board members that family considerations helped drive her decision.

Ashton Carter’s the consensus front-runner now, but I don’t see how this complicates Obama’s decision. If anything, it simplifies it a bit.