Donald Trump may prove to be the ultimate Brexiteer. Back in August 2016, in the midst of his presidential campaign, he proudly tweeted, “They will soon be calling me MR. BREXIT!” On the subject of the British leaving the European Union (EU) he’s neither faltered nor wavered. That June, he was already cheering on British voters, 51.9% of whom had just opted for Brexit in a nationwide referendum. They had, he insisted, taken “their country back” and he predicted that other countries, including you-know-where, would act similarly. As it happened, Mr. “America First” was proven anything but wrong in November 2016.

Ever since, he’s been remarkably eager to insert himself in Britain’s Brexit debate. Last July, for instance, he paid an official visit to that country and had tea with the queen (“an incredible lady… I feel I know her so well and she certainly knows me very well right now”). As Politico put it at the time, “In just a matter of a few hours, he snubbed the leader of the opposition — who wants a close relationship with the EU after Brexit and if he can’t get it, advocates a second referendum on the options — in favor of meeting with two avid Brexiteers and chatting with a third.” Oh, and that third person just happened to be the man who would become the present prime minister, Brexiteer-to-hell Boris Johnson.

Since then, of course, he’s praised Johnson’s stance — get out now, no deal — to the heavens, repeatedly promising to sign a “very big” trade agreement or “lots of fantastic mini-deals” with the Brits once they dump the European Union. (And if you believe there will be no strings attached to that generous offer, you haven’t been paying attention to the presidency of one Donald J. Trump.) In Britain itself, sentiment about Brexiting the EU remains deeply confused, or perhaps more accurately disturbed, and little wonder. It’s clear enough that, from the economy to medical supplies, cross-Channel traffic snarl-ups to the Irish border, a no-deal Brexit is likely to prove problematic in barely grasped ways, as well as a blow to living standards. Still, there can be little question that the leaving option has been disturbing at a level that goes far deeper than just fear of the immediate consequences.

Remember, we’re talking about the greatest power of the late eighteenth, nineteenth, and early twentieth centuries, the country that launched the industrial revolution, whose navy once ruled the waves, and that had more colonies and military garrisons in more places more permanently than any country in history. Now, it’s about to fall into what will someday be seen as the subbasement of imperial history. Think of Johnson’s version of Brexiting as a way of saying goodbye to all that with a genuine flourish. Brexit won’t just be an exit from the European Union but, for all intents and purposes, from history itself. It will mark the end of a century-long fall that will turn Britain back into a relatively inconsequential island kingdom.

Exiting the American Century

By now, you might think that all of this is a lesson written in the clouds for anyone, including Donald Trump, to see. Not that he will. After all, though no one thinks of him this way, he really is our own American Brexiteer. In some inchoate and (if I can use such a word for such a man) groping fashion, he, too, wants us out; not, of course, from the European Union, though he’s no fan of either the EU or the North Atlantic Treaty Organization (NATO), but from the whole global system of alliances and trade arrangements that Washington has forged since 1945 to ensure the success of the “American Century” — to cement, that is, its global position as the next Great Britain.

Not so long ago, when it came to Washington’s system of global power, the U.S. was the sun for orbiting allies in alliances like NATO, the Southeast Asian Treaty Organization, and the Organization of American States. Meanwhile, the U.S. military had scattered an unprecedented number of military garrisons across much of the planet. In the wake of the implosion of the Soviet Union in 1991, the United States briefly seemed to be not just the next but potentially the last Great Britain. Its leaders came to believe that this country had been left in a position of unique dominance on Planet Earth at “the end of history” and perhaps until the end of time. In the years after the Soviet Union imploded in 1991, it came to be known as “the sole superpower” or, in the phrase of Secretary of State Madeleine Albright, “the indispensable nation.” It briefly seemed to find itself in a position no country, not even the Roman or British empires, had ever been in.

Now, in his own half-baked, half-assed fashion, Donald Trump is promoting another kind of first: his unique version of “America First.” Two New York Times reporters, David Sanger and Maggie Haberman, evidently reminded him of that isolationist phrase from the pre-World War II era in an interview in March 2016 during his election run. They described the exchange this way: “He agreed with a suggestion [of ours] that his ideas might be summed up as ‘America First.’”

“Not isolationist, but I am America First,” he said. “I like the expression.” So much so that, from then on, he would use it endlessly in his presidential campaign.

Donald Trump has, of course, been something of a collector of, or perhaps sponge for, the useful past slogans of others (as well as the present ones of his right-wing followers in the Twittersphere). As any red baseball cap should remind us, the phrase that helped loft him to the presidency was, of course, “Make America Great Again,” or MAGA, a version of an old line from Ronald Reagan’s winning election campaign of 1980. He had the foresight to try to trademark it only days after Mitt Romney lost his bid for the presidency to Barack Obama in November 2012.

Both phrases would appeal deeply to what became known as his “base” — a significant crew in the heartland, particularly in rural America, who felt as if (in a country growing ever more economically unequal) the American dream was over. Their futures and those of their children no longer seemed to be heading up but down toward the subbasement of economic subservience. Their unions had been broken, their jobs shipped elsewhere, their hopes and those for their kids left in the gutter. In a country whose leadership class still had soaring dreams of global domination and wealth beyond compare, whose politicians (Republican and Democratic alike) felt obliged to speak of American greatness, they were — and Donald Trump sensed it — the first American declinists.

At the time, however, few focused on the key word in that slogan of his, the final one: again. As I wrote back in April 2016, with that single word, candidate Trump reached out to them, however intuitively, and crossed a line that would feel familiar today to someone like Boris Johnson in a British context. With it, he had, to put it bluntly, begun to exit the American century. He had become, as I commented then, “the first American leader or potential leader of recent times not to feel the need or obligation to insist that the United States, the ‘sole’ superpower of Planet Earth, is an ‘exceptional’ nation, an ‘indispensable’ country, or even in an unqualified sense a ‘great’ one.” He had, in short, become America’s first declinist presidential candidate, striking a new chord here, just as the Brexiteers would do in England.

As I also wrote then, “Donald Trump, in other words, is the first person to run openly and without apology on a platform of American decline.” This country, he made clear, was no longer “great.” In doing so (and in speaking out, after a fashion, against America’s forever wars of this century), he grasped, in his own strange way, the inheritance that the post-Cold War Washington establishment had left both him and the rest of the country.

After all, if Donald Trump hadn’t noticed that something was truly wrong, someone would have. As the planet’s sole superpower with a military budget that left every other nation (even bevies of them) in the shade, the U.S. had, since 2001, invaded two countries, repeatedly bombed many more, and fought conflicts that spread across much of the Greater Middle East and Africa. Those wars, when launched in 2001 (Afghanistan) and 2003 (Iraq), were visibly meant both to demonstrate and ensure American dominion over much of the planet. Fifteen years later, as Donald Trump alone seemed to grasp, they had done the very opposite.

Mr. Brexit!

By the time The Donald took to the campaign trail, the U.S. had not had a single true victory in this century. Not even in Afghanistan where it all began. In the years before he entered the Oval Office, the world’s only truly “exceptional” power had mainly proven exceptionally incapable (in ways that weren’t true in the Cold War years) of making its desires and will felt anywhere, except as a force for ultimate disruption and displacement.

Globally speaking, despite all its alliances, its unparalleled military power, and its loneliness at the top — Russia remained a nuclear-armed but fragile petro-state and China was visibly rising but not yet “super” — it looked distinctly like a great power in the early stages of decline. As not just Donald Trump’s but Bernie Sanders’s campaign suggested in 2016, there was clearly a kind of decline underway at home as well, a process of hollowing out that extended from the economy to the courts to the political system.

It was no mistake that, in January 2017, in a new age of plutocracy and degradation, a billionaire entered the White House — or that his first major domestic act (with a Republican Congress) would be a tax cut that only gave yet more to the already extraordinarily wealthy. Nor would it be strange that, for the first time, the 400 wealthiest Americans would actually have a lower tax rate than any other income group.

Though The Donald did insist that he would make this country great again, his presidency has proven a distinctly declinist one. However instinctively, however chaotically, however impulsively, he has, after all, been hard at work cracking open the American imperial system as it once existed and directing the country into a future ripe for candidates with yet redder hats and slogans.

If Boris Johnson is plugging for a Britain Last moment, Donald Trump, despite his bravado and braggadocio, has been treading a similar path for the greatest power on the planet. In his trade wars, he’s been intent on cracking open the American global economic system, whether in relation to the EU, China, or allies like Japan and South Korea. In his relations with such allies, he’s been hard at work undermining the alliances that once ensured American power and influence, even as he cozies up to autocrats and plutocrats the world over.

Of course, in October 2019, its forever wars and new trade wars notwithstanding, the United States remains the strongest military power on the planet, not to speak of the wealthiest one around. So no matter what President Trump may do, we’re not about to join Great Britain in that imperial subbasement any time soon. Still, as the Trump years should already have made clear, we are in at least the early stages of an American Brexit, globally and domestically.

When the Trumpian era ends, whether in 2020, 2024, or at some other unpredictable moment, count on this: the American global system will have been cracked open, the domestic political and judicial systems undermined further, and this country made even more unequal in a gilded age beyond compare, as well as split at least in two (“civil war”!) in terms of popular sentiment.

There is, however, a difference between a British and an American Brexit. While a British one could harm the European Union (and even perhaps the American economy), its effects (except on England itself) should be relatively modest. On our overheating orb, however, an American Brexit could take the planet down with it. We are, after all, on a world in decline.

Think of Donald Trump as the president of that decline or, if you prefer, as Mr. Brexit!