Of all Julian Assange’s undoubted talents, maybe his greatest gift is the ability to make enemies. He trusts, likes and respects almost no one. He falls out with his friends and disgusts his opponents. Now that he has been dragged kicking and shouting from the Ecuadorean Embassy in London, where he was, by all accounts, the house guest from hell, he may find few allies in the world outside.

Many conservatives despise him for supposedly imperilling national security. Liberals will never forgive him for what he did to Hillary Clinton. Numerous journalists, perhaps the majority, scoff at his effrontery in identifying as one of them. Women can never forget the never-settled claims of sexual coercion in Sweden.

He is an information anarchist — dumping vast oceans of material into cyberspace with barely a thought for the consequences. He is often portrayed as a useful idiot to Putin, an enabler to Trump.

He jumped bail in Britain, costing his too-trusting supporters a small fortune in surrendered sureties. He is rude, aggressive, pompous, self-regarding, unreasonable and even — or so say multiple sources — smelly.

There is, in short, much not to love about Julian Assange. He and I collaborated on the release of military and diplomatic documents relating to the Iraq war when I was editing The Guardian in 2010 and 2011.

We spectacularly fell out. Another party to the publication was The New York Times under its executive editor then, Bill Keller. They fell out. He hired the journalist and author Andrew O’Hagan as a ghost writer. Spoiler alert: they fell out.

Part of the problem was a deeply ingrained mistrust of mainstream media. Who decreed that they got to be the gatekeepers of information?

He veered between contempt for us and a grudging acceptance that we were a necessary evil. Within the space of an hour he could go from shouting tantrums to cool-headed strategic planning. But we were not alone in finding him an impossible partner.

And yet. The laws protecting free speech should not depend on the loveability, mental health or personal hygiene of those in the firing line.

And Assange is now very much a target — being threatened with extradition to America to face charges relating to his collaboration with the source of the 2010 WikiLeaks revelations, Chelsea Manning (née Bradley). It may be that we have to suspend our complicated feelings about the man and consider the implications for free expression.

It is interesting what Assange is not being charged with — at least for now.

To have prosecuted him for the substantive content of the stream of Manning-sourced articles, about war, torture, murder and dissembling, would have reopened many cans of worms that too many people would doubtless prefer remained forgotten. And if Assange was in the dock, why not the editors of The Guardian, The New York Times, Le Monde, Der Spiegel, The Hindu, El País and numerous others?

There was a genuine public interest in publishing details of the killing of civilians in Afghanistan and Iraq. And in the American authorities’ turning a blind eye to systemic torture and murder by its Iraqi allies in 2009.

Any mainstream news organisation would have gladly broken the news disclosed in the 2010 “collateral murder” video, with its footage from an Apache helicopter showing the killing of a dozen innocent people, including two Reuters news staffers.

It would be difficult to explain why Assange alone should be singled out for his role in the joint publications, much as I personally disapproved of him subsequently spewing out unredacted classified material across the internet.

But he is not, at least at present, charged with being the agent of a foreign power or of placing lives in jeopardy. No, the charge against Assange appears to be more modest, punishable by up to five years in prison.

The unsealed grand jury indictment boils down to two claims, neither of them new: one, that Assange conspired with Manning to try to get hold of more material, even after she had leaked hundreds of thousands of classified documents; and, two, that Assange attempted, unsuccessfully, it seems, to crack a government password.

The benign explanation is that he sought to help Manning avoid detection as the source of the material she was downloading. Others accuse him of hacking, pure and simple.

Some will deplore the act of a reporter in trying to corrupt a source into imparting a nation’s secrets, although Assange, as an Australian, owes no more allegiance to the United States than an American journalist would in trying to elicit the secrets of India or the Germans.

But many journalists would acknowledge that they would encourage sources to come up with more documents. And most reporters would see it as their sacred duty to help to protect a source.

What are the implications of successfully prosecuting such behaviour? To James Goodale, the veteran lawyer who helped The New York Times to defend the Pentagon Papers from the Nixon Administration’s hot pursuit in 1971, the precedent would be devastating.

“Should Trump’s Justice Department succeed in prosecuting Assange,” he wrote in Harper’s magazine last month, “the only safe course of action for a reporter would be to receive information from a leaker passively.”

Goodale quotes the longtime investigative reporter Seymour Hersh as telling him that he obtains classified information through a process of “seduction”, in which he spends time trying to induce the source into giving up the information.

“‘If he isn’t allowed to do that,’ he says,’ it’s the end of national security reporting.’”

Goodale worries that courts could end up routinely examining the efforts of reporters to obtain information, thereby potentially criminalising much reporting.

If such a framing of reporters’ behaviour persisted, “the result would be doubt in every case ... it will mean that the Government has created the equivalent of the UK Official Secrets Act, through judicial fiat, without any legislative action.”

So why the muted response to the threat against Assange? Goodale speculates that the reason more editors and reporters don’t leap to his support is because they don’t consider him a “proper” journalist.

In a sense they are right. Assange is a shape-shifter, part publisher, part impresario, part source, part activist, part anarchist, part whistleblower, part nihilist. And, that new 21st-century creature, part journalist.

Assange does, sometimes, carry out the function of a journalist and thus should benefit from First Amendment protection, just the same as “real” reporters.

Of course, the rather weak allegations against him may be bolstered by more disturbing charges, as United States officials seek to strengthen the case for extradition. We should judge each by its own merit.

But for the moment journalists should look beyond Assange’s erratic character and capacity for making enemies and look at the underlying issue the indictment raises.

“If the prosecution succeeds,” Goodale warns, “investigative reporting based on classified information will be given a near death blow.”

That is a narrow issue for journalists. But it should matter for a more general public. All around the world repressive regimes are successfully reducing the glare of scrutiny that the media used to shine on them.

If we believe that daylight is a necessary condition for democracy, that good societies cannot function without transparency and an agreed-upon factual basis for debate and governance, then the defence of investigative reporters, however difficult or even wrong-headed those individuals may be, is important.

Alan Rusbridger is a former editor-in-chief of The Guardian. He is principal of Lady Margaret Hall in Oxford and chairs the Reuters Institute for the Study of Journalism