UK Prime Minister Boris Johnson repeated his threat to end negotiations on Brexit following talks at the European Union (EU) summit on Thursday, amid a torrent of bellicose rhetoric.

Speaking in a televised statement Friday, Johnson accused the EU of “refus[ing] to negotiate seriously” and said the UK should prepare the UK for an “Australia-style deal”—a hard Brexit with trading done on World Trade Organisation terms. Brussels, he said, “want the continued ability to control our legislative freedom, our fisheries, in a way that is completely unacceptable to an independent country.” The UK would “embrace the alternative” and “prosper mightily as an independent free-trading nation controlling our own borders, our fisheries and setting our own laws.”

Shortly afterwards the prime minister’s spokesperson claimed, “The trade talks are over. The EU have effectively ended them by saying they do not want to change their negotiating position.” This was in reference to the communique issued by the summit on Brexit which stated only that the UK needed to “make the necessary moves to make an agreement possible” and dropped an earlier drafted call for an “intensification” of talks. Later in the evening, the UK Brexit negotiator David Frost told his EU counterpart, Michel Barnier, not to come to London as planned on Monday—but added that he would agree to talks at some point early next week instead.

Johnson is engaged in a bout of cynical brinkmanship. EU sources told the Guardian that Downing Street had seen the redraft before it was released and made clear their belief that the prime minister was engaging in political theatre. The Financial Times reports, “Tory MPs have long speculated that the prime minister would engineer some kind of political ‘crisis’ as a prelude to making concessions to secure a deal.”

Johnson’s bellicosity is in inverse proportion to the actual strength of his position—and both he and the EU leaders know it. On Tuesday Barnier mocked Johnson’s efforts to impose a “third unilateral deadline” for a Brexit deal on the upcoming summit. Johnson’s statement yesterday included the offer to “discuss the practicalities with our friends where a lot of progress has already been made…” and talks between the two sides have not in fact been discontinued. Several newspapers have referred to UK and EU sources suggesting an agreement is in sight.

There are multiple political calculations at work. Brexit is a nodal point of interlocking domestic crises confronted by the UK, the EU states and the United States, and of rising geopolitical tensions between them all.

Johnson’s nationalist declarations represent the preferred policy of his party and several key pro-Brexit Conservative backers, but his refusal to cut off talks has been mandated by the City of London and the majority of British business. Hundreds of billions of pounds are at stake in a no-deal or hard Brexit, after which the imposition of tariffs and customs checks and dislocation of supply chains would stagger the UK economy. The government’s own figures suggest a 7.6 percent decline in GDP over 15 years in the event of no-deal and a 4.9 percent decline for a free trade agreement hard Brexit.

The breakup of the UK itself is a serious possibility under these conditions. Scotland voted heavily against Brexit and that discontent is being channelled by the Scottish National Party (SNP) behind its campaign for a second independence referendum. SNP leader Nicola Sturgeon said in response to Johnson’s statement, "I feel deeply frustrated and depressed at the prospect of no deal.”

Debates over customs borders also threaten to ignite a crisis on both sides of the Irish border, risking the collapse of the Good Friday Agreement.

Johnson planned to offset these losses by securing a closer alliance with US imperialism—economically, through a preferential free trade deal, and militarily, through stepped-up participation in the war drives against Iran, China, and Russia. In the context of an America led by President Donald Trump, who christened himself “Mr Brexit” in line with his programme of “America First,” Britain was expected to pursue a hard break with the EU, dealing a political and economic blow to the union.

The US presidential elections, however, threaten to shatter this strategy. US Democrats have put the UK government on notice that any such rupture would be condemned by a Biden administration, leaving the UK out in the cold. The sections of the American ruling class represented by the Democratic Party hold to the traditional position of US imperialism that the UK should remain in—or at least as close as possible to—the EU as a pro-US counterweight to Germany and France.

They are also concerned that a collapse of the Northern Ireland Agreement would anger the substantial Irish American lobby and jeopardise the lucrative relationship between major US corporations and the Republic of Ireland, which is used as an investment platform for the European market.

During a visit to the US this September, UK Foreign Secretary Dominic Raab was given a severe dressing down by leading Democratic officials. Speaker of the House Nancy Pelosi said after a meeting with Raab, “If the UK violates its international agreements and Brexit undermines the Good Friday accord, there will be absolutely no chance of UK-US free trade agreement passing the Congress.” The sentiment was echoed by Democratic presidential candidate Joe Biden.

A chorus of voices in the media are now discussing whether a hard break with the EU would be economic and diplomatic suicide. Former Tory Chancellor and leading Remainer George Osborne wrote in the Evening Standard, “Boris Johnson would have to leave behind the Brexit tribe under a President Biden.” Even the pro-Brexit Telegraph has warned, “A Biden victory would be disastrous for Boris.”

The full scale of the crisis for Downing Street is indicated by the Times article, “Panicking No 10 dumps Donald Trump and woos Joe Biden,” which reports that Johnson’s main advisor and one of the architects of Brexit, Dominic Cummings, is now ordering Tory MPs to take a certain distance from Trump and mount a Biden charm offensive.

For both the UK and the EU, the economic and political disruption caused by a hard Brexit, coming on top of the resurgent coronavirus pandemic, would compound worsening social tensions.

Any moves towards a UK-EU deal, however, remain fraught with difficulties for the national ruling classes involved. The closer the UK comes to agreeing terms, the more pronounced divisions within the bloc over the nature of those terms become. Germany’s Angela Merkel was quick to insist after the Brexit discussion at the EU summit that “we [the EU], too, will need to make compromises,” and to call on the UK not to abandon talks. France’s Emmanuel Macron is taking a much harder line.

Macron is concerned that Brexit and any concessions on Brexit might give additional impetus to Marine Le Pen’s far-right National Rally, which would step up as the supposed defenders of French farmers and fishermen. France also anticipates benefitting from a shift in financial trade from the City of London. Moreover, its hand would be strengthened against Germany, in terms of both its economic and military weight in the EU. Germany, for the reverse reasons, is more eager to preserve as close a UK-EU relationship as possible.

In whatever form it takes, Britain’s exit will dramatically alter the relationship between these two crucial European powers and therefore the geopolitical landscape of the EU. France and Germany’s ability to provide a relatively stable political axis for Europe has to a large extent depended on the ability of each to recruit Britain as an albeit unreliable ally against the other’s opposed plans for the development of the union. Brexit kicks the third leg from under this diplomatic stool. Without the UK’s dampening influence, conflicts between the EU’s two premier states will become more volatile, under conditions where tensions between EU member states are already building over the details of a coronavirus recovery plan.

None of the potential outcomes from Brexit represent progressive alternative for the British and European working class. All the horse trading of the representatives of the ruling elite is predicated on launching a devastating assault on workers’ living standards—to make good the debts accrued by massive bailouts of the corporations during the pandemic. The divisions amongst the imperialist powers are substantially over how best to carry out this attack. For the European working class, the only means of defending its own independent interests is to reject the various nationalist programmes of their respective ruling classes and take up the fight for the United Socialist States of Europe.