A US soldier has gone on trial accused of trying to give away secrets to undercover agents who he allegedly thought were Islamic militants.
Anderson's lawyer says he is delusional
Ryan Anderson, a Muslim convert serving in the US National Guard, is charged with trying to pass information to the al-Qaeda movement.
His lawyer Maj Joseph Morse argued Mr Anderson suffered "a mental condition".
But prosecuting lawyer Maj Melvin Jenks said the court-martial was "a case about betrayal".
Mr Anderson, who was not present on the opening day of his trial, has pleaded innocent to five charges.
He faces life imprisonment if two-thirds of the officers on the panel in Fort Lewis, Washington state, find him guilty of the charges.
Mr Anderson, 27, is alleged to have signed on to extremist internet chatrooms in order to contact al-Qaeda operatives to offer services and information.
Maj Jenks said he had evidence from various sources, including text messages and email, showing Mr Anderson wanted to help enemy forces, Reuters reported.
Mr Anderson is also accused of providing agents posing as al-Qaeda representatives with documents providing some specifics about army equipment.
"This is a case about betrayal," Maj Jenks told a panel of commissioned officers on the opening day of the court-martial.
"Betrayal of our country, betrayal of our army and betrayal of our soldiers."
But in his opening remarks, Maj Morse said Mr Anderson was suffering from delusions.
"They [prosecutors] want you to believe he was a militant Muslim, that he sympathised with al-Qaeda," the defence lawyer said.
"The evidence is not going to show it. He had a mental condition."
Maj Morse has previously argued the information Mr Anderson tried to pass on was not classified and was relatively easy to find.
Mr Anderson was not of a senior rank and is not thought to have had access to highly sensitive information.
The trial is expected to continue until at least Friday.