Army Pfc. Bradley Manning, right, is escorted into a courthouse in Fort Meade, Md., before a court martial hearing Thursday. (Patrick Semansky/AP)

A military judge on Thursday rejected a defense motion to dismiss a key charge of aiding the enemy in the court-martial of Bradley Manning, the Army private who turned over hundreds of thousands of classified documents to the anti-secrecy group WikiLeaks.

Judge Denise Lind, an Army colonel, cited Manning’s extensive training as an intelligence analyst and the sheer volume of records that were leaked as reasons to allow the charge to stand.

If convicted of aiding the enemy, Manning, who was serving in Iraq when he gave 700,000 military and diplomatic documents to WikiLeaks, could face life in prison, plus 154 years on the other charges he faces.

In her ruling, Lind said that because Manning worked on and had access to intelligence reports, he would have been aware of terrorist organizations’ use of the Internet. Prosecutors said Osama bin Laden read some of the material that Manning turned over after WikiLeaks posted it.

Lind also pointed to a presentation that Manning had prepared for his unit that catalogued information security procedures — the material detailed how to identify adversaries and concluded that one should avoid posting certain information on the Internet.

She concluded that when the evidence against the defendant was viewed in “a light most favorable” to the prosecution, Manning “knowingly” provided information to the enemy. She also rejected a defense motion to dismiss charges of violating the Computer Fraud and Abuse Act.

The judge could nonetheless still find Manning not guilty of those charges when she issues her verdict. Manning chose not to have a trial by military jury.

Closing arguments could come as soon as Friday.

In its rebuttal case, the prosecution entered three tweets from WikiLeaks that Manning may have viewed to show that the organization was not a legitimate journalistic enterprise. The government also tried to enter an e-mail that Manning sent to the New York Times after WikiLeaks posted a classified video known as the Collateral Murder video. Lind did not find the content relevant, and it was not entered into the record. This line of questioning gave the defense the opportunity to enter articles into evidence that depicted WikiLeaks as an important journalism outlet, a platform “just as important as” the Freedom of Information Act.

Lind’s ruling dismayed some civil libertarians, who said it could have significant repercussions for future military whistleblowers.

“This ruling has far-reaching implications,” Elizabeth Goitein of the Brennan Center for Justice said in a statement. “You don’t need specialized intelligence training to know that terrorists use the Internet. By this logic, any military officer who discloses information to the media or posts it on the Internet could be charged with aiding the enemy. That’s not consistent with the purpose of the law, and it could have a dramatic, chilling effect on would-be whistleblowers.”

Eugene R. Fidell, a senior research scholar at Yale Law School, said the ruling could provide Manning’s attorneys with a viable line of appeal.

“I’m not at all convinced the government carried its burden,” he said. “The sheer volume of the leaked documents does not, to my mind, constitute evidence of intent to aid the enemy.”