Not since Andrew Johnson followed Abraham Lincoln have successive US presidents contrasted more vividly than Barack Obama and Donald Trump.

Their handover in 2017 suggested a late-game football substitution: the languid maestro giving way to the tenacious brute, the brisk handshake a portrait in mutual distaste.

Such eye-catching polarities of style can distract from underlying likenesses. In this case, there is one of world significance. As president, Obama challenged the idea that, while other countries have interests, the US has a calling. He favoured realpolitik and wondered aloud whether a nation can have an exceptional place in the moral order when others claim the same. (Citing Britain and Greece, he forgot France, Switzerland, Japan, India, Russia and China. )

A domestic backlash later, he caved, stressing his belief in US exceptionalism with “every fibre of my being”. Cliche from the otherwise eloquent is a reliable clue to insincerity.

It is hard to think of a president who gave so little rhetorical quarter to American ideals

That Trump commits the same heresy, minus the repentance, is captured by such headlines as “Donald Trump and the death of American exceptionalism” (New Yorker), “Trump’s America: Smaller, meaner and increasingly unexceptional” (Week) and – to cut through the pussy-footing – “RIP American exceptionalism, 1776-2018” (Foreign Policy).

Again, the “exception” he is meant to have betrayed is the moral specialness of the US, whether as a passive example to the world or as an active, blood-spilling rescuer of it. His focus on national gain is written up as Old World atavism shamefully revived in a higher-minded land.

Moral compromises

This reaction is all the stranger because America First is nothing new. Even the exceptionalists acknowledge the US territorial annexes of the 19th century, the Kissingerian chicanery of the 20th and other moral compromises. Some were needless, some sensible given the exigencies of the time and almost all consistent with normal great-power behaviour.

What is distinct about Trump, historic even, is that he does not pretend. When he cultivates Saudi crown prince Mohammed bin Salman, he cites no higher end than US arms exports and the encirclement of Iran.

When he confronts China, he does not feign interest in a global tussle between open and closed societies. He just wants to repair the US current account ledger.

It is hard to think of a president who gave so little rhetorical quarter to American ideals. Even George HW Bush, the realist’s realist, whose “chicken Kiev” speech wavered on Ukrainian independence from Soviet Russia, lapsed into the language of “beacon” and “unique responsibility” once in a while.

Trump, in contrast, talks about the US as a self-interested state among self-interested states, unique in its power but not in its existential purpose, which is to survive and prosper.

He is on the record with a more subversive remark about American exceptionalism than Obama ever ventured. “I don’t like the term,” he said in 2015, to Texan conservatives, of all people. “I think you’re insulting the world.”

Provocation to millions

If you accept that even his most ruthless foreign policies have historic antecedents, then it is the rhetoric in which they are couched that is the most radical thing about him. And among the riskiest politically.

All great powers assert their own goodness.

Britain and France told themselves that empire was a civilising project. Perhaps because of religion, however, the American desire to be thought well of is unusually pronounced, and as observable in individuals as in the state.

Trump did not end American exceptionalism. That happened long ago

To disregard it as much as Trump does is high provocation to millions of his compatriots.

It is also, if we could but see it, a small service to foreigners. This supposed epitome of American jingoism is less likely than his predecessors (or colleagues or opponents) to attribute special virtue to his nation.

This alleged case study in arrested development is more grown-up than those politicians who talk about the US as a celestial creation. This outwardly abnormal president is, in one sense, if in no others, trying to normalise his country.

Trump did not end American exceptionalism. That happened long ago, through various events, and often with good reason. What he has done is end the pretence in favour of a candidly interest-driven statecraft. The question is whether he is any good at it.

Would a Saudi leader other than Prince Mohammed buy fewer US arms? What evidence is there that current account deficits hurt a nation? If China is such a threat, why abandon that potential counter-bloc, the Trans-Pacific Partnership? Fulminate as they do, it is not the exceptionalists who have a case against Trump. It is the stone-hearted realists. – Copyright The Financial Times Limited 2018