Getting Sgt. Bowe Bergdahl out of the Army is not going to be easy.

As Army leaders consider how to handle the former Taliban captive who is accused of misconduct, their options are narrowed by an obscure personnel regulation: Because the former prisoner of war's term of enlistment expired during his five years in captivity, the Army must now grant him an honorable discharge or launch a court-martial.

"We're in an all-or-nothing situation," said Jeffrey Addicott, a retired Army lieutenant colonel and judge advocate who served as a legal adviser to the Army Special Forces and now teaches law at St. Mary's University School of Law in Texas.

The Army announced Monday that the investigation of Bergdahl has been forwarded to a top general, or convening authority, to take "appropriate action."

For now Bergdahl, 28, remains assigned to a desk job at an Army headquarters unit in San Antonio. The Army declined to release any details of the six-month investigation into the circumstances surrounding his disappearance.

Then-Spc. Bergdahl was accused of leaving his patrol base intentionally before he was captured by Taliban insurgents in 2009. Legal experts say the allegations suggest charges of desertion could apply.

One legal option is for the Army to officially refer the case for a court-martial, which would open the door for Bergdahl, if he chooses, to request an other-than-honorable discharge in lieu of the court-martial. Both Bargdahl and the Army general overseeing the case would have to agree to that arrangement.

That would allow the Army to strip Bergdahl of some of his veterans benefits and impose some further administrative sanctions, such as loss of pay and reduction in rank.

But without a court-martial, the Army may have to pay Bergdahl the back pay he's technically due because he remained on active duty during his five years in captivity. That's about $200,000, and possibly far more if the full scope of POW benefits is applied.

"I don't think the Army can have it both ways. Either he was a deserter and he deserves to be court-martialed -- or he wasn't and he is entitled to the back pay," said Greg Rinkey, a former Army JAG who is now a military defense attorney in New York.

For now Bergdahl's back pay is frozen in a back account controlled by the Army and the matter will likely remain unresolved until Bergdahl is discharged.

Rinkey said he believes the Army will ultimately opt against seeking a court martial. Questions about Bergdahl's state of mind at the time of his capture would make the charges at court-martial hard to prove, and that Bergdahl's five years in captivity would weigh in the Army's decision, Rinkey said.

After five years in captivity, Bergdahl's Taliban captors released him May 31 in a prisoner swap that also freed five Taliban leaders from the U.S. military prison at Guantanamo Bay, Cuba. He returned to good health after a short stay at military hospitals in Germany and San Antonio.

A prior investigation of Bergdahl's disappearance — conducted in 2009 long before his return — found that some members of his unit believed Bergdahl left his patrol base alone at night at least once before and returned safely.

Bergdahl was interviewed as part of the more recent investigation since his return, but Army officials have not released any details of that investigation.

Yet details of the case have been widely reported in the media, in particular the criticisms from other soldiers in his unit who believe Bergdahl intentionally left his base and as a result put the lives of many soldiers at risk.

Some soldiers believe the aggressive manhunt that Army commanders in Afghanistan ordered after Bergdahl's disappearance directly resulted in several casualties.

That controversy is likely a part of the Army leadership's considerations.

"You've got almost every single member of the platoon that says 'Yeah, he put down his weapon and left his patrol base. He voluntarily vacated himself from his place of duty.' Addicott said.

It's possible Bergdahl could be charged with the lesser offense of Absent Without Leave, or AWOL. But Addicott believes the facts suggest a more severe charge. "To me, it's desertion. He left in time of war. And I think the facts are clear."