In the military's case against Sgt. Bowe Bergdahl, the charge of desertion, with a maximum penalty of imprisonment for five years, is the lesser count and the easier one to prove, legal experts say.
The more serious one, which carries the potential for a life sentence, is a rare and obscure charge called "misbehavior before the enemy," one that left military lawyers struggling to recall the last time it was leveled against a U.S. service member.
In military justice statutes, the misbehavior charge covers a grab bag of many kinds of war-zone misconduct: causing a false alarm, running away, failing to do the utmost to destroy the enemy, throwing down your weapon or ammunition, behaving cowardly, failing to do everything practicable to assist and relieve allied troops, shamefully abandoning a command and even quitting your "place of duty to plunder or pillage."
It also makes it a crime for any service member to commit intentional misconduct that endangers the safety of a unit or outpost. That provision appears to be the one the military intends to use in its prosecution of Bergdahl. He disappeared from his remote Army base in eastern Afghanistan in 2009 and was released five years later in a swap for five Taliban detainees that was approved by the Obama administration.
The prosecution is expected to argue that the fact that soldiers had to search for Bergdahl placed them at added risk.
On Thursday, a senior U.S. official, who spoke on condition of anonymity because he did not have permission to speak publicly about the case, said there were three ways that Bergdahl could be found guilty of the misbehavior charge. First, if by merely leaving his post he inherently created danger; second, if by wandering into enemy territory, he put people in danger who had to go retrieve him; and third, and worse, if he said something to the Taliban or shared information that endangered his unit or other soldiers.
The official said he did not believe the third possibility applies in this case, because if it did, Bergdahl would have been charged with a more serious type of desertion. The desertion charge he is facing is the lowest level, he said.
Military lawyers say the bar for proving cases of misbehavior before the enemy is higher than it is for desertion. And according to Bergdahl's defense team, the Army's own investigating officer found no evidence that any soldiers were killed searching for him.
The senior military official, who has sat in on meetings about the report compiled by the two-star Army general who investigated Bergdahl's disappearance, also said Thursday that he had seen nothing to suggest that Bergdahl did anything to aid the Taliban.
The end game, outside legal experts say, could be a plea deal - one with no prison time, but where the military strips Bergdahl of back pay and of veterans' health benefits.
"You want charges in there that cover the waterfront," said Gary D. Solis, a former military judge who now teaches law at Georgetown University. "The question is how the military looks at this."
"To the Army, this has been an embarrassment," Solis continued. "The military wants him gone, and Bergdahl just wants to go home."
The defense team, he added, has indicated that the sergeant left his base because he wanted to inform commanders of "disturbing circumstances" involving his unit.
"The Army doesn't want that brought out, true or not," Solis said, adding that "there is a motive on both sides of the charge sheet" for a plea agreement.
Bergdahl's lawyer, Eugene R. Fidell, said in an interview that those "disturbing circumstances" covered a number of incidents within his unit that he felt suggested that "poor leadership was being exercised, and also that some people were not performing their jobs properly."
Fidell said the defense team was not in discussions with the military for any plea deal. He declined to comment on whether the defense team was considering such negotiations. He said the team was preparing for an Article 32 hearing - a preliminary hearing similar to a grand jury - and would be participating in a telephone conference call with the hearing officer on Monday.
Walter B. Huffman, a former Army major general and commander of the Army Judge Advocate General Corps, said he believed the military was prepared to take the case to trial, including prosecuting the misbehavior charge. But the defense team could still secure a plea deal.
"There are a lot of different ways defense counsel can pose this to the government in a way that will perhaps make the government think, 'We can get our pound flesh this way, and avoid a lot of expense,'" said Huffman, a professor at the Texas Tech University School of Law.
"On the other hand," Huffman said, "the reason the military is preferring charges is to deter this kind of behavior by soldiers, to make the point of saying, 'We will not tolerate this, and if you do something like this, we will consider it a very serious violation of the Uniform Code of Military Justice.'"