Boris Johnson talks frequently of his ambitions for “Global Britain.” He wants the United Kingdom, post-Brexit, to play a great role around the world.

In a government report published in March, he said that this is vital for the UK’s “safety and prosperity,” and definitely not a “vainglorious gesture.”

How seriously should we take Britain’s prime minister? Very, say his supporters. Here are some examples they cite. A new aircraft carrier has set off on its inaugural journey, to join Dutch and American ships patrolling the South China seas. In mid-June, the UK will host a G7 summit. In November, it will host another big gathering: the United Nations Climate Change Conference, known as COP26.

All the while, the UK is busy negotiating new trade deals with other countries, now that the EU no longer does so on Britain’s behalf. And the UK remains a nuclear power within NATO, with a permanent seat on the UN Security Council.

That’s one side of the ledger. But it’s not the whole story. Here are some things that Johnson’s critics put on the other side:

• Even after the launch of the new aircraft carrier, Britain’s navy will be only half the size it was twenty years ago, and only one-quarter the size it was in 1982. It would be impossible today to put together the task force that the navy sent that year to recapture the Falkland Islands.

• To be sure, the UK is hosting the G7 and COP26 summits, but there is no evidence that being host bestows particular influence. With climate change in particular, the key players are the United States, China, and the EU. Three months ago, the EU set out its plans to become carbon-neutral by 2050. But the UK, of course, has left the EU and is now a minor actor in the climate drama. Its own recently revised targets attracted little attention in other countries.

• All the trade deals so far concluded are essentially rollover agreements that continue the arrangements Britain had as a member of the EU. If anything, the UK is less “global” than it was, because it has become harder for the UK to trade with the EU. It faces border checks and “rules of origin” restrictions on the trade in goods assembled in the UK containing components imported from non-EU countries.

• The UK’s international development program no longer sets a shining example to the rest of the world. It was one of the few countries to meet the UN target of spending 0.7 percent of its economy on aid. However, in April, the government cut its aid budget by more than one-third, with immediate effect. Given the need to honor long-term commitments to, for example, UN agencies, the impact has been to force severe cuts on many programs. These include cutting humanitarian aid to Yemen by more than half, bilateral aid to sub-Saharan Africa by two-thirds, and funding to water, sanitation, and hygiene projects by more than four-fifths.

To these examples we should add a larger point about Britain’s place in the world. Six decades ago, Dean Acheson, who had helped to create the postwar world as U.S. secretary of state, famously said: “Great Britain has lost an empire and has not yet found a role.” By joining the European Community in 1973, Britain found a role. It became a bridge between the United States and Europe.

The bridge is not as big or strong as British leaders would like; but it has made a difference. Sharing a language, history, and culture with one, and a continent with the other, Britain was able to develop close bonds with both and help to develop common approaches to global issues.

Brexit has blown up that bridge. The UK’s relations with the EU are now cold and awkward. Britain remains friendly toward the United States, but is far less useful to Washington.

If Washington wants to deal with Europe, it now bypasses London and deals directly with Brussels, Paris, and Berlin. What’s more, U.S. President Joe Biden feels strongly about his Irish roots. He will not be impressed by Johnson’s attempts to rewrite the UK-EU Northern Ireland Protocol, which the prime minister signed less than six months ago. Anything with even the faintest whiff of British bad faith will go down badly in the White House.

Recently the prestigious U.S. Council on Foreign Relations proposed a “Concert of Powers for a Global Era.” The Council suggested that its members should be the United States, China, the EU, Russia, Japan, and India. By its absence from that list, Britain has been relegated to the second division of world powers, despite having nuclear weapons and its UN Security Council seat.

The big question is: does that matter? One of the UK’s problems is that nostalgia for past glories tends to swamp its present identity. Brexit Britain is discovering that it has little influence and less power to solve the world’s big problems—such as tackling climate change, fighting terrorism, preventing future pandemics, standing up to China, and taxing big, footloose technology companies.

All in all, the days of exaggerated self-importance are finally over. A more modest Britain is on its way. Gradually, that reality is likely to sink in. It could change the way Britain, as a nation, thinks and acts; and very possibly for the better. This was not what Johnson and his fellow Brexiters intended, but it could be their most valuable legacy.