Story highlights Writers: Pfc. Bradley Manning is one of the biggest whistleblowers in U.S. history

They say the public needs to know about the U.S. war crimes and torture he revealed

Manning should have been sentenced to the 3½ years he already served, they say

Writers: 35-year sentence reflects government's despotic desire to "send a message"

Pfc. Bradley Manning is one of the biggest whistle-blowers in U.S. history, and his case is one of the Obama administration's unprecedented seven prosecutions against national security and intelligence whistleblowers. His disclosures to WikiLeaks revealed war crimes and torture -- topics that are surely in the public's interest to know.

The fact that the mainstream media around the world reprinted the bulk of his disclosures is evidence of the clear value in knowing what our government is doing.

Manning was sentenced to 35 years, but should have been sentenced to time served already: 3½ years, 112 days of which was improper pretrial detention, also known as torture. He suffered prolonged solitary confinement and was forced to be naked.

Manning's trial was sparsely covered by the mainsteam media. The alternative media outlets who did cover the story comprehensively were faced with unprecedented secrecy, so much so that for months of pretrial proceedings, none of the court pleadings was publicly available. America should be better than secret courts and the criminalization of whistleblowing.

JUST WATCHED Manning attorneys seek Obama pardon Replay More Videos ... MUST WATCH Manning attorneys seek Obama pardon 01:31

JUST WATCHED Bradley Manning apologizes in court Replay More Videos ... MUST WATCH Bradley Manning apologizes in court 02:45

JUST WATCHED Brian Manning's extended interview Replay More Videos ... MUST WATCH Brian Manning's extended interview 08:01

JUST WATCHED Bradley Manning verdict: Messages differ Replay More Videos ... MUST WATCH Bradley Manning verdict: Messages differ 02:30

The military prosecutors asked the judge to lock Manning up for 60 years in order to "send a message." Sending a message has everything to do with politics and nothing to do with justice.

Although it was not the 60 years that the government asked for, Manning's 35-year sentence is still clearly intended to send a message for his conduct -- conduct that provided the public with evidence of clear wrongdoing and did no harm to the United States. The wrongdoers whose crimes Manning exposed enjoyed far gentler fates.

Like Manning, my whistleblower clients, former National Security Agency executive Thomas Drake , who exposed warrantless wiretapping; and former CIA officer John Kiriakou , who exposed his agency's use of torture, were charged under the Espionage Act. Unlike Manning, they were not convicted under that act, although Kiriakou is serving out a 30-month prison sentence. As in Manning's case, the only person to be truly punished was the whistleblower.

Drake and Kiriakou helped expose two of the biggest scandals of the post-9/11 era, yet they are the only two people criminally prosecuted in connection with them. The message is clear: It is safer for a government employee to violate the Fourth Amendment or to torture detainees or to gun down apparent civilians, as seen in the " Collateral Murder " video that Manning released to WikiLeaks. (That classified video shows a United States Apache helicopter firing on a group of people in New Baghdad in 2007 who do not return fire. Two of those killed were Reuters' employees; two children were severely injured. An Army investigation found the crew followed the rules of engagement).

Manning's harsh sentence and the government's despotic desire to "send a message" represents yet another dismal step toward secrecy from a presidential administration that once pledged to be the "most transparent in history."