I was in Kabul in 2010 when Julian Assange and WikiLeaks first released a vast archive of classified US government documents, revealing what Washington really knew about what was happening in the world. I was particularly interested in one of these disclosures, which came in the shape of a video that the Pentagon had refused to release despite a Freedom of Information Act request.

When WikiLeaks did release the video, it was obvious why the US generals had wanted to keep it secret. Three years earlier, I had been in Baghdad when a US helicopter machine-gunned and fired rockets at a group of civilians on the ground who its pilots claimed were armed insurgents, killing or wounding many of them.

Journalists in Iraq were disbelieving about the US military’s claims because the dead included two reporters from the Reuters news agency. Nor was it likely that insurgents would have been walking in the open with their weapons when a US Apache helicopter was overhead.

We could not prove anything until WikiLeaks made public the film from the Apache. Viewing it still has the power to shock: the pilots are cock-a-hoop as they hunt their prey, including people in a vehicle who stop to help the wounded, saying, “Oh yeah, look at those dead bastards,” and, “Ha, ha, I hit them.” Anybody interested in why the US failed in Iraq should have a look.

The WikiLeaks revelations in 2010 and in 2016 are the present-day equivalent of the release by Daniel Ellsberg in 1971 of the Pentagon Papers, unmasking the true history of the US engagement in the Vietnam War. They are, in fact, of even greater significance because they are more wide-ranging and provide an entry point into the world as the US government really sees it.

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The disclosures were probably the greatest journalistic scoop in history, and newspapers such as The New York Times recognised this by the vast space they gave to the revelations. Corroboration of their importance has been grimly confirmed by the rage of the US security establishment and its overseas allies, and the furious determination with which they have pursued Assange, the co-founder of WikiLeaks.

Daniel Ellsberg is rightly treated as a hero who revealed the truth about Vietnam, but Assange, whose actions were very similar to Ellsberg’s, is held in Belmarsh high-security prison. He faces a hearing in London this week to decide whether he will be extradited from the UK to the US on spying charges. If extradited, he stands a good chance of being sentenced to 175 years in the US prison system under the Espionage Act of 1917.

Ever since Assange orchestrated the release of documents through WikiLeaks, he has been the target of repeated official attempts to discredit him or, at the very least, to muddy the waters in a case that should be all about freedom of speech.

The initial bid to demonise Assange came immediately after the first release of documents, claiming that it would cost the lives of people who were named. The US government still argues that lives were put at risk by WikiLeaks, although it has never produced evidence for this.

On the contrary, the US counter-intelligence official who was in charge of the Pentagon’s investigation into the impact of the WikiLeaks disclosures admitted in evidence in 2013 that there was not a single instance of an individual being killed by enemy forces as a result of what WikiLeaks had done.

Brigadier General Robert Carr, head of the Pentagon’s Information Review Task Force, told the sentencing hearing for Chelsea Manning that his initial claim that an individual named by WikiLeaks had been killed by the Taliban in Afghanistan was incorrect. “The name of the individual was not in the disclosures,” he admitted.

On the day the WikiLeaks revelations were made public, I had a pre-arranged meeting in Kabul with a US official who asked what the coding on the top of the leaked papers was. When I read this out, he was dismissive about the extent to which the deep secrets of the US state were being revealed.

I learned later the reason for his relaxed attitude. The database Manning had accessed was called SIPRNet (Secret Internet Protocol Router), which is a US military internet system. After 9/11, it was used to make sure that confidential information available to one part of the US government was available to others. The number of people with the right security clearance who could theoretically access SIPRNet was about 3 million, although the number with the correct password, while still substantial, would have been much fewer.

The US government is not so naive as to put real secrets on a system whose purpose was to be open to so many people, including a low-ranking sergeant such as Chelsea Manning. Sensitive materials from defence attaches and the like were sent through alternative, more secure channels. Had the US security services really been using a system as insecure as SIPRNet to send the names of those whose lives would be in danger if their identity were disclosed, they soon would have run short of recruits.

The false accusation that lives had been lost, or could have been lost, because of WikiLeaks damaged Assange. More damaging by far are the allegations that he has faced of the rape and sexual molestation of two women in Sweden in 2010. He denies the allegations, but they have condemned him to permanent status as a pariah in the eyes of many. The Swedish prosecutor discontinued the rape investigation last year because of time elapsed, but this makes no difference for those who feel that anything Assange has said or done is permanently tainted and that the WikiLeaks disclosures are only a tangential issue. Likewise, much of the media views Assange’s character and alleged behaviour as the only story worth covering. Although information about SIPRNet and General Carr’s evidence was published long ago, few journalists seem to be aware of this.

But it is not because of anything that may have happened in Sweden that Assange is threatened with extradition to the US to face prosecution under the Espionage Act. The charges all relate to the release of government secrets, the sort of thing that all journalists should aspire to do, and many have done in Britain and the US without being subject to official sanctions.

Compare the British government’s eagerness to detain Assange with its lack of interest in pursuing whoever leaked the secret cables of the British ambassador to the US, Kim Darroch, to the Mail on Sunday last year. His negative comments about Donald Trump provoked an angry reaction from the president that forced Darroch to resign.