Last Sunday, the biggest ever donor in British political history was celebrating. The man who is currently supporting a hard Brexit campaign for Britain to leave the European Union with no deal and who is under investigation by the National Crime Agency for multiple potential offences took to Twitter to let off steam.

Arron Banks, the Bristol-based businessman who funded Nigel Farage’s Leave.EU campaign, had seen the first news reports of the special counsel Robert Mueller’s investigation into possible collusion between Donald Trump and the Russian government and he was cockahoop.

“It’s a beaut…particularly harsh on news media pumping out fake news for two years. The Russia thing was a hoax from beginning to end. @Channel4News @carolecadwalla @NewYorker @washingtonpost.” Minutes later, he added: “No Russian collusion, I’m waiting for the NNCA_UK [sic – National Crime Agency] decision and trust me, you are top of list to sue! Crazy @carolecadwalla @Channel4News and others.”

And Farage joined in: “After 2 years of conspiracy theories and Fake News journalism, apologies are owed to @realDonaldTrump and his family.”

It was the Twitter equivalent of a victory lap. As far as Banks and Farage were concerned this was the Mueller report, a report that had investigated their friend and ally, Donald Trump, and the news had entirely vindicated him of all charges.

And they treated it, as if it was their own vindication. As if Robert Mueller was investigating them. Which, if reports are to be believed, he was. In early 2017, the Guardian reported that Nigel Farage was a “person of interest” to Robert Mueller. And just a week ago, the New Yorker reported that sources close to the investigation said both he and Arron Banks had been caught up in the special counsel’s inquiry.

Trump and Farage in Washington in March. Photograph: Tia Dufour/PA

It’s striking how, two-and-a-half years on from Trump’s election, his language of fake news and conspiracy theories and hoaxes, of triumphalist bluster, and routine threats to journalists, is now a normal part of British political life. His behaviour – using intimidation to threaten journalists and organisations publishing evidence-based reporting – doesn’t even raise eyebrows any more and even the news from America elicited not much more than a baffled shrug.

The all-consuming nature of Brexit left almost no space for us to contemplate the significance of the news from America even as it demonstrated how entwined our fates are and continue to be. Last week, once again, saw an amazing confluence between political events in both countries: Brexit and Trump are perhaps better understood as movements rather than events, movements that have continued on twin train tracks since they were set in motion within months of each other in 2016, and that both reached some sort of climax last week.

The publication of the Mueller report in the US and the Brexit deadline in the UK were mirrored also by struggles between lawmakers and the executive branch. As MPs in parliament were attempting to wrest back control from a prime minister desperate to stop them at all costs, Democrats in Congress were agonising over a president who appears intent on covering up what Mueller’s report actually says.But Banks and Farage weren’t crowing at the publication of Mueller report. They were crowing about a report of the Mueller report. A four-page summary of a 300-page document that drew evidence from 500 witnesses and issued 2,800 subpoenas and whose true contents remain a mystery.

The actual report and its description of the investigation, an investigation that has led to dozens of indictments and at least eight guilty pleas or convictions including Trump’s closest aides, remains unknown.

William Barr, the attorney general, has refused to turn it over to Congress. Instead, Barr a political appointee of Trump, delivered a summary of it. He said that neither Trump nor his campaign had “conspired or knowingly co-ordinated” with Russia and presented no finding on whether he had obstructed the course of justice. It did “not conclude that the president committed a crime, it also does not exonerate him.”

And as much as Arron Banks would like it to, we do not actually know if Mueller’s report exonerates him. And whatever Mueller might have concluded, the sources of Banks’s donation to Leave.EU are still under investigation by the National Crime Agency. And we still have no answers as to why the Russian embassy targeted him and offered him lucrative business deals in the week Leave.EU launched its campaign to take Britain out of the European Union. Banks has never answered that question, preferring instead to claim a media ‘smear’, but what became clear on Sunday night was how closely both he and Farage appear to identify their own fate with Trump’s.

In Britain, the news from America should be a huge red flag. Because even while we still do not have the full report, even Barr’s summary of it confirmed something extraordinary and terrifying: incontrovertible evidence of an attack by Russia on America. Mueller’s investigation has laid out how a foreign power had used America’s own media organisations and technology platforms to subvert its own democracy.

It detailed the two major efforts: the massive disinformation campaign that we know now was run by the Internet Research Agency and paid for by the Russian government. And its hacking of Democratic party computers and the Clinton campaign, also by the Russian government, and the dissemination of the stolen documents via “various intermediaries including WikiLeaks”.

And yet, all this has been lost in a news cycle that eats its own. The threat from a hostile aggressor which the European Commission said last week would seek to cause the same havoc to the European elections in May. It warned that Russian propaganda efforts were “systematic, well-resourced and on a different scale to other countries.”

But the threat is also within. It was American technology campaigns that enabled the Russian disinformation campaign. It was American news organisations that published articles based on the WikiLeaks’ material. And it was American citizens – Trump’s campaign manager, his personal lawyer, his national security adviser and multiple campaign aides – who had secret meetings, organised back channels, lied to investigators, communicated with Russian GRU officers and, in one instance, actually handed over campaign data to a suspected Russian intelligence agent

What last week in America has made clear is that this is complex, systemic and almost impossible to disentangle from the technological and cultural foundations that underpin all American society. Russia didn’t invent the racism that the Internet Research Agency inflamed. WikiLeaks didn’t compel the New York Times to splash its stolen material on its front page day after day. And the Kremlin didn’t force Trump’s aides to lie to set up secret meetings or lie to investigators.

And what the summary of Mueller’s report has revealed is that the cavalry is not arriving. The answers to this aren’t necessarily legal; they’re political. Adam Schiff, chairman of the House intelligence committee, tore into the Republicans who looked to unseat him last week, enumerating the known facts of the investigation and concluding: “You might say that’s all OK. You might say that’s just what you need to do to win. But I don’t think it’s OK. I think it’s immoral. I think it’s unethical. I think it’s unpatriotic, and yes, I think it’s corrupt, and evidence of collusion.”

In Britain, meanwhile, there’s only deafening silence. When Caroline Lucas questioned Theresa May in parliament last month, about what the government knew about Russian attacks in Britain, she was told there had been “no successful” interference. When she submitted a follow-up question about what its unsuccessful interference had been and how “success” was defined, she received the same bland non-reply.

Banks and Farage are right to celebrate. Farage’s contacts with Julian Assange and Roger Stone – Trump’s campaign aide arrested on charges of lying to Congress about his efforts to contact WikiLeaks – lay full square within the scope of Mueller’s investigation. As were Banks and his sidekick, Andy Wigmore,’s, contacts with the Russian embassy, where they continued to have meetings in the period after Brexit while they were on the campaign trail with Trump.

But in Britain, we don’t have the bandwidth or the resolve or the understanding of the bigger picture to want to even try to understand this web of interconnected relationships. We stand by as Arron Banks and Nigel Farage ape Donald Trump. We remain incurious about the ties that connect them and the money behind them. We watch as they attack the press and seek to undermine our institutions.

The Mueller report is a warning that we won’t heed. He’s exposed Russia’s attack on America’s presidential election for what it was – a system exploit. The same system that underpins our democracy – with the same weaknesses and vulnerabilities.

A system that he has shown to be utterly broken. And the idea that a narrow legal investigation into Banks’s wealth involving unknown resources being carried out in secret as our government refuses to answer our MPs’ questions will resolve any of this is a category error. We need to know what the government is refusing to tell us. To stand up and fight for the truth. Or stand by and watch it die.