WRITING to his wife in May 1942, Evelyn Waugh recounted a true story of military derring-do. A British commando unit offered to blow up an old tree-stump on Lord Glasgow’s estate, promising him that they could dynamite the tree so that it “falls on a sixpence”. After a boozy lunch they all went down to witness the explosion. But instead of falling on a sixpence the tree-stump rose 50 feet in the air, taking with it half an acre of soil and a beloved plantation of young trees. A tearful Lord Glasgow fled to his castle only to discover that every pane of glass had been shattered. He then ran to his lavatory to hide his emotions, but when he pulled the plug out of his washbasin “the entire ceiling, loosened by the explosion, fell on his head.”

A year on from the Brexit referendum Britain feels like Lord Glasgow’s castle. The most visible damage has been done to its domestic politics. With the Conservative Party in turmoil Jeremy Corbyn, Labour’s hard-left leader, talks about being prime minister in six months. But just as serious is the blow to Britain’s global standing, which is lower than it has been at any time since the Suez crisis in 1956, when America crushed Anthony Eden’s attempt to reassert British power in Egypt.

For decades Britain’s foreign policy has rested on three pillars: the United States, the European Union and the emerging world. Winston Churchill, the son of a British aristocrat and an American heiress, coined the phrase “special relationship” to describe the ties of blood and language that bind Britain to America. As a former imperial power, Britain had close ties with dozens of African and Asian countries. With one of Europe’s largest economies, it had a big say in Europe’s future, often acting as a counter-balance to the Franco-German axis.

British diplomats can be starry-eyed about this. The Suez crisis demonstrated that America was happy to dump the “special relationship” whenever it clashed with its national interest. The British have always been second-division players in Europe. Yet the three pillars have not only stood the test of time. They have also reinforced each other. Britain’s membership of the EU bolstered its influence in America just as its close relations with America increased its clout in the EU. The EU magnified Britain’s global power, bringing with it trade deals with 53 other countries.

Britain’s decision to leave will obviously diminish its influence in Europe. Even if it can negotiate favourable access to the single market it will no longer be part of the EU’s decision-making apparatus. Its weakness has already been exposed: David Davis, Britain’s chief Brexit negotiator, has so far done little but make concessions. So has its isolation. Theresa May is now routinely asked to leave meetings when EU business is discussed.

Britain is leaving the EU at a time when its relations with the United States are perilous. Donald Trump is a volatile figure whose lodestar is “America first”. He is extraordinarily divisive, meaning that the closer Britain gets to Mr Trump the more it alienates anti-Trumpists. A survey of 37 countries by the Pew Research Centre found that just 22% of people thought that Mr Trump would “do the right thing” in international affairs. Barack Obama scored 64% in the final year of his presidency.

What of the third pillar? The Brexiteers’ strongest card is that they are globalists. Untethered from Europe’s rotting corpse, they argue, Britain will be free to engage with the emerging world. Yet there is no evidence that British companies were held back from this by EU membership. The EU hasn’t prevented Germany’s Mittelstand companies from becoming global powerhouses. The reverse might be the case: emerging countries are interested above all in access to the EU’s market of 500m people.

The self-reinforcing logic of the old system will go into reverse over the next few years, whoever sits in Downing Street. Henry Kissinger told a conference in London this week that Brexit provides a chance to renew the transatlantic relationship. But he was forgetting the question he supposedly asked when he ran American foreign policy: “Who do I call if I want to speak to Europe?” America will spend more time on the phone with a convivial power inside the EU than outside (Mr Trump is to visit France on Bastille Day, whereas his proposed trip to Britain is up in the air). Emerging markets will be more interested in dealing with great power blocks than with a small country with idiosyncratic rules and volatile politics. This could happen even faster if Britain elects Jeremy Corbyn, who has made a speciality of criticising the world’s leading powers while cuddling up to its basket cases.

From virtuous to vicious circle

Since the 1980s Britain and America have been the world’s leading apostles of the ideology of the moment, neoliberalism. British consultants travelled around Europe and the former Soviet Union offering lessons on privatisation. The Swedes introduced internal markets into their welfare state. The Germans tried to adopt “shareholder capitalism”. But neoliberalism took a beating with the 2008 financial crisis. Britain and America have since been humbled by a populist tide that produced Brexit on one side of the Atlantic and Mr Trump on the other. Brexiteers argued that a Leave vote would produce a “Brexit spring” as the ancien régime tottered and the euro plunged. Instead, the EU is in its best shape in years, with a young reformer installed in the Élysée Palace and the Franco-German axis solid. Across the continent the press talks of Britain as the “sick man of Europe”.

In the aftermath of the Suez crisis, Dean Acheson lamented that Britain had lost an empire and failed to find a role. In the subsequent decades, post-imperial Britain in fact found several roles: as a fulcrum between Europe and America; as an old hand at globalisation in a re-globalising world; and as a leading exponent of neoliberalism. Thanks to the combination of the financial crisis and Brexit, it has lost all of these functions in one great rush. The windows have shattered and the ceiling has fallen in.

Economist.com/blogs/bagehot