The true extent of Russian meddling has still to come to light

It was an image guaranteed to fan the flames of Islamophobic hatred of the streets of Britain. A Muslim woman wearing a hijab is filmed walking nonchalantly past the prone bodies of injured and dying victims of the Westminster Bridge terror attack in London last March without the least concern for their well-being.

The image was posted on the internet, supposedly by a Texan tourist, shortly after British-born terrorist Khalid Masood mowed down a number of civilians on Westminster Bridge before being shot dead, after he had stabbed an unarmed policeman to death outside the Palace of Westminster.

The post immediately went viral and could easily have led to increasing ostracism of Britain’s mainly peace-loving Muslim community as it seemed to suggest a callous disregard for human suffering.

Only now it transpires the post was not genuine but a deliberate fabrication dreamed up by a Russian internet troll factory that is said to be operating in St Petersburg.

According to US investigators looking into Russian meddling in last year's presidential election contest, the video post was a deliberate attempt by the Kremlin to exploit the first major terror attack on the streets of Britain for a decade to sow the seeds of racial disharmony, with the aim of causing further social and political disharmony in the UK.

The revelation that the post of the Muslim woman on London Bridge was yet another example of the fake news being pumped out by Russian president Vladimir Putin's internet fantasy factory is one of the most graphic illustrations we have seen of the length the Russians are prepared to go to undermine the West by any means possible.

As a former senior KGB officer, Mr Putin is well-versed in the black arts of international espionage and is said to have used his skills to good effect in undermining Western democracies during the Cold War.

Now it seems he is applying the same skill set to use the opportunities afforded by the World Wide Web to achieve the same aims by peddling fake news.

The true extent of Russian meddling in last year's US presidential election has still to come to light, but hardly a day passes without American prosecutors finding evidence of some new, egregious example of Russian misconduct.

Earlier this month, Facebook said it estimated that the fake news pumped out by Moscow's troll farm had reached an estimated 150 million subscribers during the election campaign. What effect this had on the outcome of the contest is hard to estimate, but the growing amount of evidence suggests the Kremlin orchestrated a well-run campaign to prevent Democratic candidate Hillary Clinton from reaching the White House. This includes allegations that the Trump team collaborated with WikiLeaks, the organisation run by Australian activist Julian Assange. It published a number of damaging emails relating to the Clinton campaign, which appear to have been obtained by Russian hackers.

It would be a sublime irony if Mr Assange, who likes to portray himself as the ultimate anti-establishment crusader, was instrumental in helping Mr Trump to win the White House. But then Mr Assange has enough credibility problems after he was forced to seek refuge in the Ecuadorian embassy in London five years ago over his refusal to answer sexual harassment allegations in Sweden.

But while the main focus of attention regarding Russian manipulation of the internet for its own ends has mainly been on America and last year’s presidential contest, the revelations concerning the fake Muslim woman post show that the Kremlin’s ambitions to destabilise the West lie far beyond the United States.

Given that Mr Putin’s aim is to destabilise and unsettle Western countries and institutions that he regards as posing a threat to his own territorial ambitions, it comes as no surprise that evidence is now starting to emerge in London of Russian meddling in last year’s controversial Brexit referendum.

Earlier this week, it was revealed that more than 150,000 Russian-language Twitter accounts posted tens of thousands of messages in English, urging Britain to leave the European Union in the days before last year's referendum.

More than 400 of the accounts that Twitter has already identified to congressional investigators as tools of the Kremlin also posted divisive messages about Britain’s decision on withdrawing from the bloc, or Brexit, both before and after the vote.

Most of the messages sought to inflame fears about Muslims and immigrants in a clear plot to affect the outcome the vote. The British authorities have now set up three inquiries into allegations of Russian meddling and the mounting evidence concerning Russian efforts to subvert Britain's democratic institutions is the reason why prime minister Theresa May decided to make such a hard-hitting anti-Russian speech this week, where she argued that Russia was using the twin tools of cyber attacks and online propaganda to "undermine free societies" and to "sow discord in the West".

The recent political crisis in Catalonia is another occasion where negative Russian interference has been identified. The Russians have no interest in Catalan independence per se. But the fact that a successful campaign by Catalan separatists to achieve independence would severely weaken Spain, a key member state of both the EU and Nato, was clearly too good an opportunity to miss. Consequently, Russian cyber-warriors were busily occupied during the campaign peddling alarmist fake news to the effect that the referendum could ultimately lead to a new Spanish civil war, or worse.

Clearly, Mr Putin and his troll factories remain committed to undermining Western democracies by any means possible. And it is up to the West to be vigilant to make sure that fake news does not triumph at the expense of true facts.

Con Coughlin is the Daily Telegraph’s defence and foreign affairs editor