The photograph shows a man on the ground, curling into a foetal position, one hand over his face, being beaten by four, or maybe five burly men wielding short truncheons. Two are in the act of striking, and one may have just delivered his blow. Most of them show that strange anxiety that violent policemen seem to have that, unless they're quick, they won't get another chance to whack the defenceless man.

The picture seems to demand a reaction. These bullies must be stopped, mustn't they? But the picture also suggests our helplessness. The man seems to be on his own, and by today he won't even have a foreign cameraman there to capture his beating.

Perhaps the governments of the enlightened world ought to make a fuss about it, recall ambassadors, threaten boycotts and other measures. Perhaps threaten not to recognise the returning administration of President Ahmedinejad, that messianic hick, who lives with his head in Paradise and his feet in corruption.

It is true that, as of yesterday, Iran's Supreme Leader, Ayatollah Khamenei (chosen by the Assembly of Religious Experts 20 years ago, and not subject to any term limits, save the ultimate one) promised an investigation into the contested Iranian election. This was a real concession, since he had saluted Mahmoud Ahmadinejad's victory - but we surely know what the result of his inquiries will be. One or two little glitches, some unnecessary scrutinising of voters' ballot papers in Northern Khorasan, nothing much to see, now move along.

There is a rather pleasant irony here. Iran's elections are not internationally monitored, so it is hard to know what to make of the allegations of electoral fraud. It is also a repeated and forgivable sin of sympathetic reporters to overestimate the strength of liberal reformers and to underestimate the sheet-anchor vote out in the largely unvisited sticks. But there are some results that Iran watchers describe as being very weird - and they are all very weird in Mr Ahmadinejad's favour. It's as if Gordon Brown not only won the next election, but his brother ousted David Cameron in Witney by a landslide.

What seems inherently unlikely is that we have just witnessed the greatest fraud in electoral history, and that Mir Hossein Mousavi, the main challenger, actually won. Yet the problem for Iran's leaders is that almost no one in the world, and many of their own people, will never believe that now. And they deserve to be thought guilty of stealing an election, with their history of manipulation, bullying, censorship, state violence, candidate-disqualification, torture and signal-jamming. Minors are still executed in Iran, religious minorities are persecuted, journalists can still die in prison and bloggers be prosecuted for anti-state activities. Why accept the Supreme Leader's word on anything?

And our post-Bush governments will do exactly nothing about it all. They will express a modicum of concern, while briefing that they have to face reality - which is an Ahmadinejad presidency - and tailor their tactics accordingly. There will be little gained even from the glint, let alone the rattle, of sabres. The brave Iranian reformers cannot expect much from that quarter.

The governments are probably not wrong. The truth is that the Iranian reform movement was not helped by eight years of George W. Bush, and the association of liberalism with US intervention has allowed the regime, in the words of one NGO I spoke to yesterday, to “manipulate a sense of encirclement”. In fact, even the less lefty NGOs go to almost comical pains to suggest the complex and “sophisticated” nature of Iranian society, for fear that they might be stoking up some neocon invasion fantasy.

But what does that mean for those of us who want to help the man on the floor in the photograph, and all his friends and comrades in the reform movement? Let us be honest about one thing, the demonstocracy will not be turning out for this one; only the sins of our Government or of Israel's, will have their placard factories working full-time. So how about campaigns led by, say, Human Rights Watch and Amnesty? What about “adopt a radical”?

The best answer, Tom Porteous of Human Rights Watch says, is what he calls advocacy - putting the information out there, again and again and again. Such an approach may not have brought down the regime in Burma, Porteous argues, but it has helped to keep Aung San Suu Kyi in our thoughts and our newspapers. And although the Iranian opposition is split, disorganised and operates under threat, it always manages to find some political space. What can be done is to help them to get their message over, not so much in the West, but in Iran itself and the rest of the region, and in neighbouring powers such as Russia and China. Mr Porteous had to break off our conversation to prepare for a fundraiser (“it's all I ever seem to do sometimes”), which suggests one way in which the rest of us might assist.

Another is to use the personal technology of globalised communication to enable contact between Iranians and people in other countries. A viral message campaign was organised on Facebook during the Iranian election - just as it was in last November's US presidential election - allowing users to encourage each other to vote. Right now several Iranian bloggers are being linked to by British news sites.

One twitterer (can we not find a more dignified term?) posted earlier that he was going to the opposition rally in Tehran, typing: “It's worth taking the risk, we're going. I won't be able to update until I'm back. Again thanks for your kind support and wish us luck.”

The luck will be of his own and other Iranians' making. They will have to decide what they can endure and what kind of movement they can build. We can only watch and wave. But there was a second version of the photograph I referred to earlier. In this version, published on the front page of The Times yesterday, we see the same man and the same beating. But this picture is bigger, and we see that one of the assaulting coppers has turned round and is facing away from the victim. Coming towards him are a number of people, including two women dressed in black, and they are clearly shouting at the policemen to stop. Am I wrong to interpret this policeman's stance as being nervous?

The difference between the two versions is the difference between despair and hope - and it is all about Iranians themselves.

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