Donald Trump could deliver the most serious blows to Brexit, according to a new analysis, as his trade policies and stance on NATO reshape the debate over Britain's future relationship with the European Union.
A decade after the Brexit vote, those who regret the decision are increasingly hopeful that Britain is on a trajectory back into the bloc. The irony, according to David Williamson, Chief Political Commentator, is that Mr Trump will have delivered several of the most serious blows if Brexit somehow dies.
Trade barriers replace free trade dreams
Idealists who wanted to break free from Brussels's grip loathed the protectionist instincts of eurocrats and had a passion for free trade. The great prize was unfettered trading with the United States.
But Mr Trump believes in erecting trade barriers rather than tearing them down. His enthusiasm for tariffs is even stronger in his second term in power, as he fights to protect the steel and auto industries and insists that products for American consumers are made in America.
The dream that the US might join the likes of the UK, Australia, Mexico and Japan in the CPTPP trade partnership has evaporated, with the Democrats now also worried about the impact of cheap imports on US workers.
Security concerns shift the debate
Sir Tony Blair's think tank argues that we are now in an era of great power competition between the United States and China and that "Britain should play a leading role in shaping a more powerful Europe".
But it is not just economics which has so radically changed the soundtrack to the debate about Britain's future relationship with the EU. It is the possibility that Ukraine could explode into a continent-torching conflagration, plus the gnawing fear that the NATO alliance could unthread.
It is one thing for the President to demand the UK and European states invest more in defence – lots of generals and plenty of ordinary people would agree that we have underfunded our armed forces for decades – but it is another order of disruption to announce a mega-deal for Russia to supply diesel fuel and demand Volodymyr Zelensky step down when Ukraine is fighting for its survival.
NATO's future and European unity
Past presidents relished their role as the "leader of the free world" but Mr Trump has no desire to cast himself as a transatlantic guardian. Vladimir Putin's threat to democracies which were once under the boot of the Kremlin has forced European military and political players to talk to one another with unprecedented seriousness about mutual defence.
If Mr Trump's legacy is a withered NATO then its European members will have to bind even closer together to deter Russia.
Champions of Brexit will argue with ardent conviction that the UK can hold onto its precious, restored sovereignty while taking every necessary measure to defend this realm and protect our allies. But Mr Brexit is handing ammunition to those who want Britain back as a fully-fledged member state.
