Britain’s sense of purpose in the world is trending downward. Indisputably, Thursday’s election marks a new low in national ambition, and it’s likely to be followed by a further, perhaps accelerating, decline. British voters seem to think the country’s global standing no longer matters. The truth is, they’re right.

The realization has been a long time coming. It’s 60 years since the Suez crisis showed Britain how little of its hard power was intact after the catastrophe of the Second World War. Yet the country gradually developed two ideas about how to remain unduly influential nonetheless. The first was its supposed “special relationship” with the U.S.; the other was its role as a leader in Europe.

The two goals seemed to fit. Britain would be most valuable as a U.S. ally by being America’s friend inside the European Union — guiding Europe away from wishing to question or challenge U.S. leadership. But the combination never gelled.

Margaret Thatcher, ardent admirer of the U.S., prized the special relationship but couldn’t look at Europe without shuddering. Her loathing of the European project ended her political career. Tony Blair didn’t make that mistake: He was all for Europe, but his misadventure in Iraq inflicted fatal damage on his own mid-Atlantic conception of Britain’s place. Following America’s lead, he took the country into a war his country remembers as disastrous and unnecessary. For this, he remains unforgiven — and when Ed Miliband, Labor’s current leader, recently said that his government would work “with our allies, never for them,” he was talking about Blair.

Today’s Tories, for their part, don’t disagree. Look at the government’s decision, over strenuous U.S. objections, to make Britain a founding member of China’s new infrastructure bank. Or consider its cuts to defense spending, which have aroused questions in Washington about Britain’s capacity to be an effective military partner. The issue hardly figured in the election debates. No more special relationship? That’s fine, think most Brits. What did the special relationship ever do for us?

Ditto Europe. Britain is uncomfortable, and probably always will be, in its European home. It won’t ever quite belong. The U.K. Independence Party (UKIP) is channeling that frustration. UKIP will win hardly any seats in this election — but the support it’s drawn from the Tories will most likely deny Prime Minister David Cameron a parliamentary majority, and it has forced him to pander to anti-E.U. sentiment and promise a referendum on Britain’s E.U. membership.

Labor has rightly criticized Cameron’s pledge of “an in/out referendum on an arbitrary timetable.” Yet it has promised an in/out referendum of its own “in the unlikely event of a transfer of powers from Britain to the E.U.” Such a transfer, in due course, is far from “unlikely”; transferring power to the E.U. is ultimately what the E.U. is for. It’s what “ever closer union” — its founding principle — means.

For the time being, anyway, Britain will have more pressing questions to address. The issue of Scottish independence, far from being settled by last year’s referendum, will return with a vengeance when the Scots send a big delegation of anti-Britain representatives to Westminster — big enough, perhaps, to lock the Tories out of power. Voting reform will reappear on the agenda. Constitutional innovations such as “English votes for English laws” will have to be considered. The outlook is frantic introspection.

So out in the middle of the Atlantic Britain will stay — more loosely bound to the U.S. on one side and to Europe on the other, occupied with its own governance challenges and counting for less in the world, year by year.

It sounds uninspiring, but it needn’t be such a bad thing. Britain is a medium-sized island nation: A measure of insularity seems to go with the territory. Or, to put it more positively: A foreign policy guided by enlightened self-interest rather than by delusions of relevance has a lot to recommend it.

What does enlightened self-interest dictate? First, that Britain shouldn’t take its alliance with the U.S. for granted. It can’t expect America’s unconditional support, and it shouldn’t offer the U.S. its own — yet a strong convergence of interests ties the countries together. It’s stupid to undermine that friendship needlessly, as Cameron did over the Chinese bank. More important, Britain must take care to remain an ally worth having. If Britain continues to cut its defense spending, it won’t be.

So far as Britain’s future in the E.U. is concerned, Britain is already semidetached — by virtue of its wisdom in standing aside from the euro project. The goal of such a patently reluctant partner cannot be to lead Europe from the inside, a platitude that Britain’s pro-E.U. politicians, Labor and Tory alike, are fond of reciting. Instead, the aim should be to codify and regularize its associate-member status, allowing a two-speed Europe to emerge and be recognized.

Britain, on the whole, is right not to regret its loss of influence. Prudence and self-interest will do more for the country — and for international relations — than nostalgia.