Julian Assange has paid a heavy price for his leaks - the US should let him go home | Simon Jenkins

The Julian Assange farce has run its time. He should be left to return to his homeland of Australia. Yet another appeal against successive British court decisions to extradite him to the US has been allowed. It merely prolongs the tedium. Washington should consider Assange's more than a decade on the run to be penalty enough for his past sins. It should not want to see its own record in Afghanistan and Iraq revived before the court of world opinion.

Like many freelancers in the undergrowth of espionage, Assange is no knight in shining armour. Phone hacking is an infringement of privacy to which he first pleaded guilty in 1996 in Australia. He then graduated to state secrets. Some such secrets may require the protection of the law, including those concerning individuals as well as private advice and information. Others undoubtedly merit public concern.

Assange regarded all as fair game. In 2010 his organisation, WikiLeaks, published thousands of documents leaked by a dissident US security analyst, Chelsea Manning. Manning had been shocked at what she had seen of the conduct of Americans in Afghanistan and Iraq. This included hundreds of gratuitous killings left unreported, including the machine-gunning of civilians from a helicopter. The casual cruelty perpetrated and tolerated by staff on the ground was revealed. The US government said the revelations placed individuals at "risk of serious harm, torture or even death". Others were horrified.

Three years later, another US intelligence whistleblower, Edward Snowden, showed his shock at the abuse of power by the US National Security Agency, often in collusion with other nations' security services. These included gross invasions of personal liberty, persistently concealed from Congress. Both Snowden and the media organisations with whom he collaborated, including the Guardian, were careful in revealing only material that was clearly in the public interest and did not endanger individuals. This even included checking with security contacts.

Assange showed no such concern. Manning was tried and sentenced to 35 years in prison in 2013, though her sentence was commuted by the then US president, Barack Obama, in 2017. Assange became a scarlet pimpernel. He had arguments with his media outlets about what to reveal or not reveal, which he saw as censorship. While Manning languished in jail, he avoided extradition to Sweden over an allegation of rape and then to the US for his revelations, taking refuge in the Ecuadorian embassy in London for seven years. During this time he was visited by celebrities and managed to meet his partner, Stella Moris, whom he later married in London's Belmarsh prison.

Relations between London and Washington are such that extradition requests are usually granted. Assange's lawyers defended him on the improbable basis that he might face execution on US soil. Constant appeals to British judges saw this thesis rejected. Washington lawyers said four to six years in jail was more likely. He has been held on appeal in Belmarsh since.

Two things tell in Assange's favour. The first is that the worst of his revelations unquestionably merited exposure. Aerial bombardment is the cruellest weapon of war, as we are seeing in Ukraine and Gaza. Manning, Assange and their media collaborators performed a public service in revealing the recklessness that war induces in those who wage it. They also highlighted the risk of moral outrage turning security staff into whistleblowers - as was the case with Snowden.