One trial balloon to replace fired Defense Secretary Chuck Hagel has crashed almost as notably as it arose. Leaks from the White House last week suggested that Barack Obama might name Homeland Security Secretary Jeh Johnson to replace Hagel, given Johnson’s time as chief counsel for Defense and his short tenure in national-security policy circles. ABC News reports that the White House has now popped the balloon they inflated in the first place:

Just last week, Homeland Security Secretary Jeh Johnson was a top contender to be nominated as the next Defense Secretary. But senior officials tell ABC’s JONATHAN KARL it will not be Johnson. He is now the third potential nominee who is no longer under consideration. A source close to Johnson says that he did not take himself out — it was a White House call.

That’s a very strange sequence of events from the White House, and speaks to the incoherence of their overall national security policy. Johnson was a strange choice for a Hagel replacement anyway. Hagel at least had some connection to the troops through his own service and policy interest in veteran affairs, even if he lacked any track record on strategic policy and organizational success. Johnson doesn’t even have that much going for him.

On top of that, Johnson is currently fronting Obama’s executive action on immigration, which has raised the ire of Congress. A Johnson nomination would give Senate Republicans two opportunities to rake the White House over the coals over Obama’s unilateral actions in confirmation hearings: Johnson’s at Defense, and Johnson’s replacement at Homeland Security. In fact, that’s precisely where Johnson will be today, on Capitol Hill defending Obama’s actions:

At a hearing scheduled before the House Homeland Security Committee on Tuesday morning, Johnson will defend President Barack Obama’s plan to shield millions of undocumented immigrants from deportation, saying they are “not removal priorities,” according to his prepared testimony obtained by CNN.

“Many of these individuals have committed no crimes and are not enforcement priorities. It is time that we acknowledge this as a matter of official policy and encourage eligible individuals to come out of the shadows, submit to criminal and national security background checks, and be held accountable,” Johnson is expected to tell the committee.

CNN reported just a few minutes ago that the White House has now settled on a long-time Pentagon technocrat as Hagel’s replacement instead:

Ashton Carter to be nominated for Defense Secretary, barring last-minute complications, sources tell @barbarastarrcnn pic.twitter.com/juE0PGAiwr

— CNN Breaking News (@cnnbrk) December 2, 2014

That makes sense on a political level, and perhaps an organizational level as well. It won’t help what really ails the Obama administration’s defense policy, though, which is that it’s being controlled by his inner circle rather than truly independent policymakers. Unlike George Bush’s decision to bring in Robert Gates in 2006, which helped change the strategy in Iraq and the approach to national-security policy, Carter’s appointment will mean the same incoherence that allowed the White House to float Johnson’s name last week as a trial balloon will continue. He won’t have the political clout to force an independent point of view within Obama’s inner circle, and Carter will just be another chess piece to sacrifice later when more failure results.

Update: Barbara Starr and Jim Acosta report that the deal is done with Carter: