Former Army Sgt. who served with Bergdahl: 'He is at best a deserter, at worst a traitor'

(CNN) – For five years, the soldiers who served with Bowe Bergdahl largely stayed silent about his disappearance, and the efforts to find him. Many of them were asked by the military to sign non-disclosure agreements about the matter.

But now that he is free, they are coming forward to talk, regardless of the consequences.

"He is at best a deserter, and at worst a traitor," says former U.S. Army Sgt. Josh Korder. Korder served with Berghdahl in Blackfoot company, 2nd platoon in Afghanistan, and was recently discharged from the military.

Questions surround the circumstances of Bergdahl's disappearance. Conflicting details have emerged about how the militants managed to capture Bergdahl. Published accounts have varied widely, from claims that he walked off the post, to claims he was grabbed from a latrine.

According to firsthand accounts from soldiers in his platoon, Bergdahl, while on guard duty, shed his weapons and walked off the observation post with nothing more than a compass, a knife, water, a digital camera, and a diary.

"Any of us would have died for him while he was with us, and then for him to just leave us like that, it was a very big betrayal," Korder said in an interview with CNN's "The Lead with Jake Tapper."

At least six soldiers were killed in subsequent searches for Bergdahl, and many soldiers in his platoon said attacks seemed to increase against the United States in Paktika province in the days and weeks following his disappearance. Korder has the names of two of them tattooed on his back.

"As soon as he is able and as soon as he is fit, I do believe that he needs to be questioned, and basically tried if necessary," said Korder.

The military may punish Korder for talking about the circumstances surrounding Bergdahl's disappearance and the subsequent hunt for him, but the former Army sergeant said he had to speak out.

"I don't think that I could have continued to go on without being able to share with you and ... the people the true things that happened in this situation. Because if you guys aren't made aware of it, it will just go on, and he'll be a hero, and nobody will be able to know the truth," said Korder.