Accused whistle-blower Bradley Manning turned 24 on Saturday. He spent his birthday in a pre-trial military hearing that could ultimately lead to a sentence of life ... or death. Manning stands accused of causing the largest leak of government secrets in United States history.

More on Manning shortly. First, a reminder of what he is accused of leaking. In April 2010, the whistle-blower website WikiLeaks released a video called Collateral Murder. It was a classified US military video from July 2007, from an Apache attack helicopter over Baghdad. The video shows a group of men walking, then the systematic killing of them in a barrage of high-powered automatic fire from the helicopter. Soldiers' radio transmissions narrate the carnage, varying from cold and methodical to cruel and enthusiastic. Two of those killed were employees of the international news agency Reuters: Namir Noor-Eldeen, a photojournalist, and Saeed Chmagh, his driver.

Renowned whistle-blower Daniel Ellsberg, who released the Pentagon Papers that helped end the war in Vietnam and who himself is a marine veteran who trained soldiers on the laws of war, told me: "Helicopter gunners hunting down and shooting an unarmed man in civilian clothes, clearly wounded ... that shooting was murder. It was a war crime. Not all killing in war is murder, but a lot of it is. And this was."

The WikiLeaks release of the Afghan war logs followed months later, with tens of thousands of military field reports. Then came the Iraq War Diaries, with close to 400,000 military records of the US war in Iraq. Next was Cablegate, WikiLeaks' rolling release (with prominent print-media partners, from the New York Times to the Guardian) of classified US State Department cables, more than 250,000 of them, dating from as far back as 1966 up to early 2010. The contents of these cables proved highly embarrassing to the US government and sent shock waves around the world.

Among the diplomatic cables released were those detailing US support for the corrupt Tunisian regime, which helped fuel the uprising there. Noting that Time magazine named "The Protester," generically, as Person of the Year, Ellsberg said Manning should be the face of that protester, since the leaks for which he is accused, following their impact in Tunisia, "in turn sparked the uprising in Egypt ... which stimulated Occupy Wall Street and the other occupations in the Middle East and elsewhere. So, one of those 'persons of the year' is now sitting in a courthouse."

Another recently revealed Cablegate release exposed details of an alleged 2006 massacre by US troops in the Iraqi town of Ishaqi, north of Baghdad. Eleven people were killed, and the cable described eyewitness accounts in which the group, including five children and four women, was handcuffed, then executed with bullets to the head. The US military then bombed the house, allegedly to cover up the incident. Citing attacks like these, the Iraqi government said it would no longer grant immunity to US soldiers in Iraq. President Barack Obama responded by announcing he would pull the troops out of Iraq. Like a modern-day Ellsberg, if Manning is guilty of what the Pentagon claims, he helped end the war in Iraq.

Back in the hearding room at Fort Meade, Maryland, defense attorneys painted a picture of a chaotic forward operating base with little to no supervision, no controls whatsoever on soldiers' access to classified data, and a young man in uniform struggling with his sexual identity in the era of "don't ask, don't tell". Manning repeatedly flew into rages, throwing furniture and once even punching a superior in the face, without punishment. His peers at the base said he should not be in a war zone. Yet he stayed, until his arrest 18 months ago.

Since his arrest, Manning has been in solitary confinement, for much of the time in Quantico, Virginia, under conditions so harsh that the UN special rapporteur on torture is investigating. Many believe the US government is trying to break Manning in order to use him in its expected case of espionage against WikiLeaks founder Julian Assange. It also sends a dramatic message to any potential whistle-blower: "We will destroy you."

For now, Manning sits attentively, reports say, facing life in prison for "aiding the enemy." The prosecution offered words Manning allegedly wrote to Assange as evidence of his guilt. In the email, Manning described the leak as "one of the more significant documents of our time, removing the fog of war and revealing the true nature of 21st century asymmetrical warfare." History will no doubt use the same words as irrefutable proof of Manning's courage.

• Denis Moynihan contributed research to this column.

© 2011 Amy Goodman; distributed by King Features Syndicate