The Union Jack and the tricolour flag of Ireland waved side-by-side in Belfast, the centre of decades of violence, as Catholics and Protestants came together in protest of mass immigration.

More than 25 years after The Troubles ended with the Good Friday agreement in 1998, the British Isles tethered on the cusp of another ethno-nationalist conflict divided down sectarian lines of race and religion.

“Civil War is inevitable,” said billionaire Elon Musk amid the chaos that ensued after three girls were murdered at a Taylor Swift dance class.

Mr Musk says a lot of things. His entry into the UK tinderbox, however, doused kerosene over a Labor government struggling to prevent an all-out war between anti-immigration protesters and a counter-protest coalition waiving the banners of Palestine, Antifa, and the LGBT rainbow flag. There were also flags emblazoned with white Arabic writing on a black background.

Prime Minister Keir Starmer established a “standing army” of 6000 riot police, expanded prison capacity by at least 500, opened courts 24/7, rolled out mass surveillance and censorship programs, and mobilised 41 out of 43 territorial police forces in England and Wales in one of the largest law enforcement operations in Britain’s history.

“Let me also say to large social media companies and those who run them,” Mr Starmer said after an emergency meeting of police chiefs. “Violent disorder, clearly whipped up online, that is also a crime, it’s happening on your premises, and the law must be upheld everywhere.”

False information boosted on Twitter, Facebook, Telegram, and TikTok has been widely cited as the spark to more than a week of fiery clashes between violent offenders, police and counter-offenders.

Prince Harry, on a tour of Colombia, said “people in positions of influence” over the spread of misinformation should “take more responsibility”.

“We are no longer debating facts,” he said, adding that people are “acting on information that isn’t true”

“What happens online within a matter of minutes transfers to the streets,” he said.

“For as long as people are allowed to spread lies, abuse, harass, then social cohesion as we know it has completely broken down.”

Critics say the spark was lit by a knife-wielding maniac indiscriminately stabbing up a holiday dance class and killing three children, Bebe King, 6, Elise Dot Stancombe, 7, and Alice da Silva Aguiar, 9. A day later, riots began outside a mosque in Southport and quickly spread throughout the cities and backwaters of Blighty, from Liverpool to London; Birmingham to Belfast.

Social media posts claimed the suspect was a Muslim immigrant named Ali Al Shakati who illegally arrived in the UK by boat last year. The so-called Shakati was supposedly known to authorities, used Liverpool mental health services, and was “on MI6’s watchlist”.

In reality, the suspect charged with three counts of murder and 10 of attempted murder, Axel Muganwa Rudakubana, 18, is the son of immigrants from Rwanda and was born in Wales. A plea hearing has been set for October 25, with a preliminary trial date of January 20.

The former head of MI6, Sir Richard Dearlove, said Russia’s fake news about the Southport stabbings is part of Vladimir Putin’s “grey warfare” against the West.

The source was traced back to a dubious website called Channel3 Now. It has administrators based in Pakistan and the United States, but its IP address is obscured. The tenuous Russian connection comes from an associated YouTube channel that began 11 years ago posting videos of Russian rally cars, according to the Bureau of Investigative Journalism.

Disinformation researcher Marc Owen Jones said there were at least 27 million impressions for subsequent posts speculating the attacker was a Muslim or migrant, spread by influential accounts including Andrew Tate, Darren Grimes, Anthony Fowler and Tommy Robinson.

The claim was also boosted on Twitter/X by @EndWokeness, a popular account with 2.8 million followers; including Mr Musk. Mr Starmer’s thinly veiled salvo at Mr Musk and the users of Twitter/X was not an empty threat.

Stephen Parkinson, the Director of Public Prosecutions of England and Wales, said “dedicated police officers are scouring social media” for the “incitement of racial hatred”.

“So if you retweet that, then you’re republishing that, then potentially you’re committing that offence,” Mr Parkinson said.

Despite Mr Parkinson’s focus on Twitter/X, the first arrest for the offence of incitement of racial hatred came from its competitor Meta, whose president of global affairs, Nick Clegg, is the former deputy prime minister of the UK.

Jordan Parlour, 28, from Seacroft, Leeds, did not take part in any unrest due to a broken heel, but instead pleaded guilty to making his feelings known on Facebook.

“Every man and his dog should smash the f**k out of the Britannia Hotel,” he said in one post. “Cos they are over here living the life of Reilly, off the tax you hardworking people earn, when it could be put to better use,” he added in another.

Violent offenders targeted hotels used to house foreigners, with a mob targeting a Holiday Inn Express housing 235 asylum seekers in Rotherham – home of the grooming gang cover-up scandal in which authorities failed to act on organised child sexual abuse from the late 1980s to 2013.

Almost 500 have been arrested since the riots broke out on July 30, with 140 charged. That included Labor’s Dartford councillor Ricky Jones, who was suspended from the party and arrested on suspicion of “encouraging murder”.

“They are disgusting Nazi fascists and we need to cut all their throats and get rid of them all,” a man, alleged to be Mr Jones, says in a video shared by the Met police. The crowd of counter-protesters cheered at the suggestion.

At the peak, police prepared for 100 rallies and 30 counter rallies after channels on the encrypted Telegram messaging app circulated a list targeting mosques and immigrant centres, including the officers of lawyers representing the Muslim community.

That flashpoint never materialised. It was unclear if the feared list of targets was a hoax to divert resources, or if the plot was deterred by the tens of thousands of protesters that showed up to combat it.

There were still more than 20 cities where the violence flared in the week of unrest, including Manchester, Hull, Bristol, Stoke-on-Trent, Blackpool and Middlesbrough, among other places. An estimated 110 officers, as well as police horses and dogs, were reported injured in the initial count of casualties.

Peter Farrelly, COO of British insurance broker Sedgwick UK, said initial claims include significant fire, theft and malicious damage losses across the retail, education and public sectors. At this early stage, estimated claim numbers are around 10 to 15 per cent of the volume of the 2011 London riots.

The overwhelming majority of British people, 85 per cent, do not support the violent unrest, according to a YouGov survey. Social media is viewed by 86 per cent as an immediate driving force.

But beyond “immediate triggers”, more than two-thirds, or 67 per cent, believe that immigration policy is an instigating factor responsible for the riots, protests and unrest.

The influence of social media has been largely overstated to stigmatise millions of ordinary people and silence objections to mass immigration and its effects, according to pollster and University of Kent professor, Matthew Goodwin.

“These protests are just the tip of the iceberg. What lies beneath are millions of decent, hardworking, patriotic British people who have simply had enough of these disastrous policies, of being told they are ‘racist’ or ‘far right’ for wanting to change course, and who are routinely shut out of the national conversation,” Mr Goodwin said.

“If you knew nothing about Britain and watched BBC News you really would think all this chaos is the direct result of a social media campaign led by Tommy Robinson and Elon Musk,” he added.

As Mr Musk went to war with “Two-Tier Keir” over criticism of Mr Starmer’s crackdown, British MPs threatened to haul the billionaire to answer for the spread of “misinformation” and “racial hatred” on Twitter/X.

Bonnie Spofforth, 55, was the first arrested over an alleged tweet claiming the Southport stabbing suspect was fake immigrant “Ali Al-Shakati”.

Britain’s Online Safety Act, which gives the UK the power to fine social media companies up to 10 per cent of global turnover, won’t come into effect early 2025.

With fears the start of the English football season on August 16 could lead to more disturbances, the people of Britain began searching for their own ways to calm the growing storm.

In Belfast, the loyalists and nationalists united as the anti-immigration protesters chanted “Islam out” and smashed the windows of the Sahara shisha cafe.

In Birmingham, there was hope. After a white man was brutally beaten by a group of Palestinian-flag-waving men outside the Clumsy Swan, leaving pub-goers terrified, Muslim activist Naveed Sadiq arrived at the scene to apologise.

“It must have been horrifying,” Mr Sadiq told one local left cowering inside the pub. “Hopefully we can put this behind us as a bad experience,” he added. “We are one”.