FORT MEADE, Md. — The military hearing against Pfc. Bradley Manning closed on Thursday, with lawyers and onlookers alternately portraying the young soldier as a traitor who acted with premeditation and as an emotionally troubled whistle-blower.

In their summary arguments — bringing a close to proceedings held over nearly a week to determine whether there is enough evidence to court-martial Private Manning — military lawyers accused him of deliberately using his training as an intelligence analyst and his security clearances to leak tens of thousands of classified diplomatic cables, intelligence reports and a video of a military helicopter attack that left 11 people dead.

The prosecutors showed what they described as a propaganda video by Al Qaeda in which a terrorist operative cited the leaks as useful for identifying targets for attack. One prosecutor, Capt. Ashden Fein, pounded on a podium and said Private Manning “aided in the publication of those files, knowing that our enemies would use those files.”

Private Manning’s lawyers did not argue that he was not responsible for the leaks. However, they likened the military’s case to a “Chicken Little response,” saying that none of the information funneled to the antisecrecy organization WikiLeaks had damaged national security and that the government was overcharging their client, who faces life in prison.