Unborn generations will take some persuading that it all began with washing machines. In three years, the US-China rift has widened from the banalities of trade to something like a clash of philosophic systems.

An original belligerent, Donald Trump, seems ever tamer in retrospect. Imagine the former US president invoking the “freedom-loving nations” against Beijing, as his secretary of state did last year. Or setting out to disprove, like his successor Joe Biden, that “autocracy is the wave of the future”.

Mercantile cynicism has its uses. A current account imbalance is negotiable in a way that “values” are not. If Trump was the first US leader since Jimmy Carter to not start a new war, that welcome omission flowed from something dark: his indifference to the internal depredations of foreign governments. Those who cheer the return of idealism in US statecraft do so well-meaningly. But then they must also budget for the messy implications.

The stress on values does not just raise the stakes of the superpower contest. It also ties America’s hands in the winning of it. Biden has set out on the long game of weaving a network of states (“alliance”, never mind “coalition”, seems too much) that worry about China. This month’s visit to New Delhi by defence secretary Lloyd Austin was suggestive. So too was the inaugural summit of the Quad that links India, Japan and Australia to the US.

This diplomatic work is harder, and the resulting strength in numbers more formidable, than direct confrontation with Beijing. To that extent, Republican slurs about Democratic softness on China are as asinine as ever. Once more, though, liberal values have perverse consequences. The US can be morally scrupulous. It can string together a mighty web of friends. But it cannot achieve both feats at the same time.

Is the US going to refrain from courting, say, Thailand, on the basis of its lapses into junta rule or its lèse majesté laws? As the Philippines blows hot and cold, will Biden stop bidding for its loyalty if its populist government breaks a liberal norm too many? As for the largest potential friendship of all, that with India, is there anything Prime Minister Narendra Modi could do there to make the US spurn so grand a prize?

None of these are fantastic hypotheticals. They are real, recent or plausible scenarios. And they say nothing of the yet harder choices that await the US outside Asia. In countering Chinese, or Russian, influence in the Middle East and Africa, Biden can hardly operate a “democracies only” rule for local allies. Too many countries flunk that test but remain tantalisingly poised between the big powers. It would be an act of masochistic self-denial to let them slip into a rival’s morally undemanding patronage. But then, after the “America is back” noises, it would be a loss of face to embrace illiberal partners.

In this way, the administration will hit its head from time to time against the moral bar it has set itself. The more rigorously Biden applies US values, the narrower his strategic options will be. The more he observes them in the breach, the higher the cost in US trustworthiness and credibility. For a 78-year-old man, the predicament is only softened by its eerie familiarity. His country struggled with it for much of his life.

The US-Soviet conflict was an inexact trailer for today’s great power tussle. Communism was a mostly closed world: a “cold war” with the globe’s number one goods trader will take some doing. Still, one theme promises to hold and that is the company the US had to keep, or felt it had to keep, against the lapping tides of communism. The Greek colonels, the Pakistani generals, the gallery of rogues in Latin America: it was at times a flexible sort of free world that America led.

If anything, the temptation of moral compromise is far stronger now. The frontline of the cold war was Europe, which had democratic governments in place from Dublin to Bonn. There are prominent examples of those in Asia, the new zone of competition, but there are also military rulers, technocratic city states, one-party systems, vulnerable democracies and established ones trending the wrong way.

If Antony Blinken’s commitment to “support democracy around the world” while abjuring force is to mean anything, the secretary of state must be willing to pass up convenient relationships out of liberal principle. The regional winner, if he does, hardly needs naming. And so he probably won’t. There is no disgrace at all in such pragmatism. But there is disillusion and acrimony stored up in pretensions to the opposite.

janan.ganesh@ft.com