A controversial proposal that aims to end the military's "up-or-out" rules for officer military promotions remains a source of debate and disagreement among the Pentagon’s top leaders brass, a top defense official said.

The proposal to reform the federal laws that regulate officer careers was central to Defense Secretary Ash Carter's slate of personnel reforms — he called it "Force of the Future" — outlined last year. But the military's top four-star officers balked and the matter remains under review.

"It is still in the deliberative process. Let me just say it’s been a fulsome debate," Deputy Defense Secretary Robert Work told Military Times said in a recent interview.

Changing the 1980 law known as the Defense Officer Personal Management Act, or DOPMA, could fundamentally redefine the officer corps’ career tracks, where promotions are mainly based on seniority rather than demonstrated talents and skills. The initiative could apply to the military's enlisted force as well, but that would not require congressional action to change federal law. The individual services have the authority to adjust enlisted manpower policies as needed to shape size and makeup. [[[RETOOLED THIS GRAPH SOME AND ADDED TWO SENTENCES TO CLARIFY THE ENLISTED ISSUE. OK?//A.deG.]]]

The matter was vigorously debated by the Joint Chiefs of Staff in one of their recent meetings in the Pentagon E-Ring conference room known as "the tank."

"It's gone to a tank and so everyone knows about it and the chiefs have been able to weigh in," Work said. "Once we have it all buttoned up and we've addressed all the concerns … that is when we announce" a final reform proposal.

Last year Carter called for sweeping change to the military personnel system, in some ways mirroring the private sector. [[[ADDED THAT CLAUSE. OK?//A.deG.]]]no problem//at He said today’s rigid military career tracks may be discouraging some of the nation's best and brightest young people from pursuing a military career.

Specifically, the reforms could change or end the "time in grade" requirements that standardize today's' military career tracks. That would allow the most talented officers to move up the ranks more quickly.

Reforms could also revise or eliminate the cap on the number of times an officer can be passed over for promotion before being forced to leave service (typically two times for most officers). Removing those up-or-out caps could encourage officers to pursue nontraditional assignments or develop technical expertise without fear that their career progression will suffer.

Carter has formally announced several personnel reforms as a part of his "Force of the Future" initiative, but several big changes discussed last year, including up-or-out reform, have stalled. In late-February, Senate Republicans attacked the ideas as "an outrageous waste of time" while criticizing the Pentagon’s nominee to implement them. [[[ADDED THIS LAST SENTENCE. OK?//A.deG.]]no problem//at] 

The Army and Marine Corps leaders have resisted the change most forcefully, while Navy and Air Force leaders have signaled some support for the changes, according to several officials familiar with the internal debate. [[[CAN WE SUMMARIZE WHY ARMY/USMC ARE RELUCTANT TO CHANGE?//A.deG.]]they are just more old-school and don't rely as much on ]

Today's up-or-out rules can foster a military culture that rewards "careerist functionaries," said Dan Grazier, a former Marine Corps captain and tank officer who is now a national security expert with the Project on Government Oversight in Washington.

"You have to be a 'yes man' and suck up to your immediate boss because if you get one bad [performance review] you get passed over for promotion and if that happens twice you get forced out," Grazier said. [[[DO WE KNOW WHAT HE DID? GRUNT? PILOT? LOGISTICIAN? WOULD BE GOOD TO SAY AT WHICH RANK HE LEFT, TOO. THAT MIGHT PROVIDE CONTEXT FOR HIS VIEWS//A.deG.]]added above//at]

Reforming the DOPMA regulations would "help foster a culture of moral courage, which is definitely useful on the battlefield," Grazier said.

Questions about officer promotions come at a time when other key personnel issues have created a political tug-of-war between the top brass and it's civilian leadership.

For example, Carter recently approved opening all combat jobs to women despite some resistance from the Marine Corps. He's also expected to soon clear the way for transgender troops to serve openly. And he recently expanded maternity leave despite some reluctance from the uniformed leadership.

Carter and his civilian allies may have viewed officer personnel reform as forcing too much change on the military.

"Taking on the brass on this was seen as going too far," said one official familiar with the debate. "Maybe they were afraid of a civ-mil divide being more apparent up at the highest level."

Nevertheless, the opposition is not as strong as it was a couple of years ago, according to another defense official familiar with the debate.

"It's kind of like the seven stages of grief, where finally you're at the state of acceptance, and I think that is where folks are getting to," he said.