As the court-martial winds down for the US soldier accused of the largest leak of classified information in the nation’s history, military prosecutors will try to portray him as arrogant and reckless, while the defence will seek to show he was well-meaning but naive.

Private First Class Bradley Manning, 25, faces 21 counts of leaking more than 700,000 documents related to the wars in Iraq and Afghanistan to the WikiLeaks anti-secrecy website. The most serious charge, aiding the enemy, carries a life sentence.

The case has pitted civil liberties groups who seek increased transparency into the actions of the US military and security apparatus, against the government, which has argued that the low-level intelligence analyst, who was stationed in Baghdad at the time, endangered lives.

Army Colonel Denise Lind, who is presiding over the trial, last week rejected a request by the defence to throw out the aiding-the-enemy charge, saying that Manning’s military training made it clear to him that any information released on the internet could get into the hands of enemy agents.

“He was knowingly providing intelligence to the enemy,” Lind said.

The case, which saw WikiLeaks publish classified files, combat videos and diplomatic cables, serves as a test of the limits of secrecy in the Internet age.

Manning was arrested in May 2010 while serving in Iraq.

In February, he had pleaded guilty to lesser charges, including misusing classified information, such as military databases in Iraq and Afghanistan and files pertaining to detainees at Guantanamo Bay.

Manning chose to be tried by a military judge, rather than have a panel of military jurors hear his case.

The defence attempted to portray Manning as well-intentioned but young and naive, while the prosecution maintained that he was a trained intelligence analyst who knew what the fallout of such a major leak would be.