The Royal Air Force celebrated its 100th birthday last week with a gala program at the Smithsonian Institution’s National Air and Space Museum in Washington. No one does pomp better than the British, but the presence of the Queen’s Colour Squadron had a larger purpose: to solemnize the reformation of 617 Squadron, the famous Dambusters, now flying the stealthy F-35. Those 16 fighter jets are among the best in the world. Given how few planes the RAF has, they’d better be. As a nation, Brexit Britain is stepping out of the shadow of the EU. But as a military power, it’s stepped into the shade.

The defense of a nation is about a lot of things. But ultimately, it takes money. One of Britain’s proudest boasts is that it’s one of the few members of NATO to meet the alliance’s target of spending a minimum of 2 percent of GDP on defense. By NATO’s figures, the U.K. spent 2.12 percent in 2017, more than any other member of NATO except Greece and the United States. But NATO’s accounting includes military pensions as defense spending. An alternative estimate, by the respected International Institute for Strategic Studies, found that Britain missed NATO’s minimum target in 2017 for the second year in a row—this time, by over $1 billion.

The rot set in years ago. As far back as 1998, in the second year of Tony Blair’s Labour government, a review of Britain’s defenses acknowledged that “the so-called ‘peace dividend’ from the ending of the Cold War has already been taken.” Yet while he waged wars in the former Yugoslavia, Sierra Leone, Afghanistan, and Iraq, Blair continued to cut the defense budget, which fell from 3.5 percent of GDP in 1996 to 2.3 percent in 2007. That was lower than at any point in the 20th century except 1930, 1932, and 1933—the depths of the Great Depression.

Then, after 2007, Britain cut some more. Since 2010, the British armed forces have shrunk from 198,000 total personnel to 161,000—a 19 percent decrease and one that occurred under Conservative or Conservative-led governments. As of mid-April, the U.K.’s National Audit Office found that the British military was short 8,200 personnel—“the largest gap in a decade.” The British defense procurement plan, too, according to the audit office, is “not affordable,” and the efficiencies promised to close the gap suffer from “a lack of transparency.” In other words, they don’t exist.

All of this is drearily familiar. For two decades, British governments have promised to square the funding circle by achieving greater efficiencies, a promise first heard in that 1998 review. For two decades, the efficiencies achieved have failed to keep the declines in defense spending from gnawing into the size and strength of Britain’s forces. For two decades, British defense secretaries have tried to fill “black holes” in the defense budget and to ride procurement “bow waves” caused by major defense programs that always cost more than shrinking budgets allow. This time around, the potential shortfall is 20 billion pounds.

What’s even more disturbing are the lies the British tell themselves to make all this seem okay. There is the lie that today’s equipment is so much better than yesterday’s that it doesn’t matter how little of it they have. Leaving aside the obvious fact that even the best plane can’t be in two places at once, the problem with this lie is that buying one plane doesn’t get you one plane on the front line: Given training and maintenance, it gets you about a third of a plane, which is much less useful. The same goes for ships: Last month it was reported that of the Royal Navy’s 19 frigates and destroyers, only 5 were available for operations, and that cannibalization of vessels for spare parts is now “routine.”

Worst of all, though, is the British lie about the nature of war. In the early 2000s, British military thinkers began to advance the comforting and ridiculous theory that the future of warfare was known, and that, by happy chance, what Britain needed to buy was precisely the lighter and cheaper equipment it had decided it could afford. As one influential report put it as late as 2009, for Britain to focus on state-on-state war was to adopt “a vestigial Cold War mindset.” Today, this narrow-minded, cost-driven vision has left Britain unprepared for great-power conflict and with a mere 227 battle tanks—just a shade fewer than Russia’s 20,000.

The problem isn’t that Britain lacks ambition. British forces lead NATO’s multinational battlegroup in Estonia, and by late 2018 Britain will have three warships enforcing U.N. sanctions off the Korean Peninsula. Britain has committed to conducting a freedom of navigation operation in the South China Sea in 2018. Compared to Germany, which is both politically feckless and militarily incontinent, Britain is brilliant. But Britain’s can-do military culture and its political willingness to deploy mean that Britain is taking on far more risk than it realizes, and on margins that are almost comically slender.

In the end, Britain’s problem isn’t money. It’s the absence of leaders who are able to advance a vision for Britain’s world role that would justify spending more money on it. Downing Street stepped forward in early 2018 to develop “a cross-government strategy on loneliness,” of all things. But like every government since the departure of Margaret Thatcher’s, it lacks a strategy for mattering in the world. The green shoots of strategic thought growing at British think tanks (like the increasingly influential Policy Exchange) are a hopeful sign, but it shouldn’t be hard to recognize that when Britain exits the E.U., it will once again be an independent nation at the center of Winston Churchill’s three circles—the United States, Europe, and the Commonwealth. Britain’s role is to stand at the center of the West, connecting, uniting, and fortifying it.

That’s a role worth taking—and worth defending. But as it is, we have a Britain that wittily promised, at the RAF’s anniversary party, to throw a bash for the U.S. Air Force when the American centenary rolls around—in 2047. That’s a good joke. Let’s hope the RAF has enough personnel left by then to keep that pledge.