Brexit was meant to make Britain global. It has made us friendless

It is not a secret that Britain is leaving the EU. The coronavirus crisis has dominated 2020 but not obliterated memory of the years before. Still, to be on the safe side, the government is spending £93m on a Brexit refresher campaign with the slogan “check, change, go”.

This is aimed at people who have dealings with Europe and might be under the illusion that it will be as easy in the future as it has been in the past. No one has done more to cultivate that misapprehension than Boris Johnson. The government’s new message on Brexit is to disregard what the prime minister used to say on the subject.

The essential issue here is that Brexit can make EU membership go away, but not the EU itself. When the only problem was being inside, escape was the only solution worth talking about. Hardline Eurosceptics were no more bothered by the issue of how an ex-member state might manage relations with Brussels than arsonists are interested in what to do with ashes.

As a result of that complacency, the UK does not have a policy towards the EU, only an impulse away from it and that is of fading relevance. No one followed us out. The fire didn’t catch.

It is important to distinguish strategic European policy from the detail of borders, tariffs and regulations. The UK has a detailed agenda for that stuff and negotiations are ongoing. If those talks fail, there is always the World Trade Organization (as Brexit ultras never tire of pointing out). But even if it were economically sensible to fall back on WTO rules (and it isn’t), the question of Britain’s geopolitical alignment would still remain unanswered.

The rubric for the current talks is “the future relationship”, but the UK has narrowed the discussion to exclude everything apart from trade. Johnson took foreign policy, security and defence cooperation – the stuff of which international alliances are made – off the table. European leaders were baffled by that choice, which seemed to defer discussion of something no less urgent than fish quotas and customs declarations, and more important in the long term.

The UK position is consistent with the Eurosceptic doctrine of pristine sovereignty. In that view, EU institutions eat national power. Every programme, even something as ostensibly benign as the Erasmus scheme for student exchanges, is a trap. The whole point of new “global” Britain, as an upgrade from the old European version, is that it is freer to deal with other global players peer-to-peer.

The limitations of that approach are quickly becoming clear. In January, the government announced that it would allow Huawei, the Chinese telecoms company, a limited role in developing British 5G infrastructure. Yesterday, the limit became an exclusion, starting next year.

The shift follows pressure on Johnson from Tory MPs who complain, with good reason, that Huawei has the potential to be a conduit for Beijing security interests and want its kit stripped out of the network even sooner. The more decisive factor is US sanctions against the company and the demand from Washington that Britain be more demonstrative in its transatlantic loyalty. The unambiguous message from the White House is that trade and security policy are intertwined. A country that wants a deal to access US markets can expect to have its foreign investment relations vetted for intimacy with undesirable states. Beijing has warned of trade retaliation against countries deemed hostile to Huawei.

Any prime minister would prioritise the security alliance with the US over a commercial deal with China. But Johnson happens to be the first prime minister to be confronted with the choice in stark, binary terms, because his trade policy is a blank sheet of paper and Donald Trump is holding the pen.

As an EU member, Britain’s trade deals were brokered by the European commission, which mobilised the scale of the single market – 28 countries; 450 million consumers – as leverage in negotiations. That is what concessions in national sovereignty buy, and every government that has felt the benefits considers it a price worth paying. The UK was no exception. David Cameron was a casual Tory Eurosceptic, happy to play-fight against Brussels banditry, but when the choice became real he campaigned to remain. Would Johnson have been a leaver if his Downing Street ambitions had come to fruition five years earlier and he had spent some time hobnobbing with fellow heads of government at EU summits? I doubt it.

In less volatile times an independent seat at the WTO would have been meagre compensation for losing Britain’s influence as one of the big three EU members. As international trade policy gets ever deeper submerged in geopolitical manoeuvres, that swap looks like the worst part-exchange in strategic history, even if you throw in a new royal yacht and call it Britannia.

Johnson knows it, too. If the prime minister thought the WTO was where the action happens, he would nominate a credible, intelligent statesman with a reputation for probity as Britain’s candidate to be the next director general. He offered Liam Fox instead. (Fox will not get the job.)

The UK is sliding into a strategic void because its only foreign policy is a plan that devalues old European alliances and shifts the balance of power to other continents when trying to make new deals. Johnson cannot address this challenge without exposing the basic flaw in Brexit, which is that the sovereignty he so jealously demands from Brussels buys no clout in Washington, Beijing or anywhere else.

The UK national interest requires a new strategic partnership with the EU, but Johnson refuses even to include that concept in the negotiation. The obstacle used to be confidence that Britain had no need of Europe. It looks now more like fear of admitting how much of Europe Britain still needs.

• Rafael Behr is a Guardian columnist