The sentence was more severe than many observers expected, and is much longer than any punishment given to any previous US government leaker.
The 25-year-old soldier was convicted last month of leaking more than 700,000 classified documents and video. The disclosures amounted to the biggest leak in US military history.
He was found guilty of 20 counts, six of them under the Espionage Act, but was acquitted of the most serious charge of “aiding the enemy”.
A three-year protracted legal process that started in May 2010, when Manning was arrested while stationed in Iraq, was over in less than two minutes on Wednesday morning.
The military judge presiding over the court martial, Colonel Denise Lind, walked into the courtroom at Fort Meade military base at 10.15am, dealt with some court admin, asked Manning to stand, then told him he was sentenced to 35 years.
She said Manning’s rank was reduced in grade, to that of Private E1. He will also forfeit pay and allowances and be dishonourably discharged, though he was not fined.
After the judge left the court, Manning was quickly ushered out by guards. A handful of supporters were heard to shout “We’ll keep fighting for you Bradley” and “You’re our hero”.
The 1,294 days Manning has already spent in military custody, since May 2010, will be deducted from his sentence. The figure includes 112 days that is being taken off the sentence as part of a pre-trial ruling in which Lind compensated Manning for the excessively harsh treatment he endured at the Quantico marine base in Virginia.
He has to serve a minimum of a third of his sentence, meaning he will be eligible for parole in just over eight years, and, at the very earliest, could be released under parole soon as 2021. He can earn 120 days per year off his sentence for good behaviour and job performance.
Manning faced a maximum possible sentence of 90 years, although few legal experts expected he would receive anything near that amount.
Prosecutors had asked the judge to jail Manning for at least 60 years. But observers who closely followed the Manning trial regarded a sentence of around 20 or 25 years as something of a benchmark.
If the prosecution had ended the trial in February, when Manning pleaded guilty to some of the counts against him, his maximum jail term would have been 20 years.
In mitigation, the soldier’s defence team said he should receive no more than 25 years – the period of time after which many of the materials he released would have been automatically declassified.
The sentence was immediately criticised by press freedom groups and civil liberty campaigners.
Ben Wizner, director of the American Civil Liberties Union’s Speech, Privacy & Technology Project, said: “When a soldier who shared information with the press and public is punished far more harshly than others who tortured prisoners and killed civilians, something is seriously wrong with our justice system.
“A legal system that doesn’t distinguish between leaks to the press in the public interest and treason against the nation will not only produce unjust results, but will deprive the public of critical information that is necessary for democratic accountability.”
He added: “This is a sad day for Bradley Manning, but it’s also a sad day for all Americans who depend on brave whistleblowers and a free press for a fully informed public debate.”
Daniel Ellsberg, who faced charges under the Espionage Act for leaking the Pentagon Papers documenting the Vietnam War, said Manning “doesn’t deserve to spend another day in jail”.
“There are some that will not be deterred even by prospect of life in prison – I think that Manning was one of those,” he said. “I think that Edward Snowden is another – he knows he faced the prospect of life in prison or even assassination. … This is an effort to minimise truth telling.””
“This is unprecedented,” said Liza Goitein, who co-directs the Brennan Center for Justice’s Liberty and National Security Program. “It is dramatically longer than the longest sentence ever served for disclosing classified information to the media, which was two years.”
WikiLeaks, however, hailed the sentence as a “significant strategic victory”. In a statement posted on the organisation’s website, WikiLeaks founder Julian Assange called the trial “an affront to basic concepts of Western justice.” Assange said “the Obama administration is demonstrating that there is no place in its system for people of conscience and principle” and warned “there will be a thousand more Bradley Mannings.”
Civil liberties campaigners say Manning’s punishment represents a dangerous escalation in the crackdown on government leakers and journalists who write stories about national security based on disclosures that have not been sanctioned by the government.
Manning is one of seven people have been charged under the Espionage Act for leaking classified information under the Obama administration. Another is Edward Snowden, the former National Security Agency contractor who turned whistleblower, disclosing top-secret details about US surveillance programs.
Snowden, 30, whose disclosures about NSA surveillance tactics were published in the Guardian and Washington Post and have already led to a raft of proposed legislative changes, some of which are backed by the White House, said he fled the US because he does not believe he would receive a fair trial.
Manning’s sentence may also give a foretaste of what could await Assange, who US prosecutors say communicated directly with Manning around the time he made the leaks.
Assange, 42, has been holed up in the Ecuadorian embassy in London for more than a year, as part of his efforts to avoid extradition to Sweden, where he faces allegations of sex crimes against two women – claims he denies.
He says he fears he will eventually be extradited to the US, where a grand jury is believed to have indicted him over the publication of classified material.
Meanwhile, a New York Times journalist, James Risen, has been told he faces a possible prison sentence if he does not cooperate with the prosecution of a CIA agent accused of leaks.
Military lawyers specifically urged Lind to jail Manning for the “majority of his remaining life” to deter potential future leakers from passing journalists documents on such a scale.
Captain Joe Morrow, a lawyer for the government, told the judge on Monday that is was her responsibility to ensure the military “never see” another leak on the scale of Manning’s releases. “This court must send a message to any soldier contemplating stealing classified information,” he told her.
Manning’s sentence vastly outweighs any previous sentence given to a US leaker, although the nature and scale of Manning’s disclosures was unprecedented.
Government workers successfully convicted for unauthorised disclosures in recent years include Shamai Leibowitz, an FBI translator who was sentenced to 20 months after passing secret transcripts to a blogger, and John Kiriakou, a former CIA officer who was sentenced to 30 months after pleaded guilty last year to disclosing information about the waterboarding of terror suspects.
In 2011, another government whistleblower, Thomas Drake, who shared information about National Security Agency technologies with a Baltimore Sun reporter, was sentenced to 240 hours of community service after a plea bargain.
The sentence marks the end of a long journey for the soldier, which began in late 2009, when he was stationed in the Iraq desert as an intelligence analyst. Disillusioned over the war, Manning, from Oklahoma, began downloading documents from classified computers onto CDs.
Manning passed 250,000 State Department cables and 470,000 Iraq and Afghanistan battlefield logs to WikiLeaks, as well as files pertaining to detainees held at Guantanamo Bay, and video of a 2007 attack by a US helicopter gunship in Baghdad that killed a dozen people, including two Reuters journalists.
WikiLeaks published some material on its site and also shared documents with a consortium of news organisations, led by the Guardian.
Manning was arrested in May 2010, after Adrian Lamo, a computer hacker who conversed with the soldier in online chats, shopped him to the FBI.
He pleaded guilty to some of the charges in February, and probably achieved some reduction of his sentence when he told the judge earlier this month that he regretted his actions and was sorry that his leaks “hurt the United States“.
Unlike civilian courts, where there are federal tariffs or sentencing guidelines, the sentence in a military court is subject to the sole discretion of the judge.
The case will now be automatically referred to the Army Court of Criminal Appeals, the first step in what could become a protracted legal battle that could potentially culminate at the US Supreme Court.