FORT MEADE, Maryland — The trial of Bradley Manning, the US soldier accused of "aiding the enemy" by giving secret documents to WikiLeaks, enters its final stage Thursday as both sides present closing arguments.

Three years since Manning's arrest in Iraq over what officials call the biggest national security leak in America's history, his defense lawyer, David Coombs, and prosecutor Major Ashden Fein will have one last chance to make their case before a military judge delivers a verdict.

The 25-year-old former intelligence analyst already has admitted to leaking hundreds of thousands of classified documents to the anti-secrecy website WikiLeaks. But he is fighting more serious charges, including the most serious count that he knowingly assisted Al-Qaeda through his massive document dump.

The court-martial has taken on new significance in the wake of dramatic revelations from another young man working with classified information, Edward Snowden, a former intelligence contractor who recently blew the lid on US surveillance of phone records and Internet traffic.