After last year’s shock US election result, many critics of Donald Trump had hoped he would grow into the presidency and heed its reasonable conventions. Not so.

After more than six months, his administration has been characterised by chronic chaos and toxic infighting (two chiefs of staff and two press secretaries, not to mention serial leaking); by an unprecedented laxness in the use of language (outgoing communications director Anthony Scaramucci’s profanity-laced interview to the New Yorker); by an inability to pass any key legislation, notwithstanding Republican Party control of Congress (last week’s failure to repeal Obamacare); by an inability to establish and then respect priorities (vacillation over Syria, North Korea); and by an inability to staff key official positions (of the 570 key agency positions requiring Senate approval, only 50 nominees have been confirmed). Above all, there is no adult supervision in this White House.

Hardly any serious American thinker disagrees with this litany of charges. Left-leaning liberals view it with a mixture of dismay and a smug I-told-you-so satisfaction, while conservatives either vent their anger or try to change the subject. In between, there is much sighing and shaking of heads.

Abroad, leading newspapers and commentators use strong language, expressing not the customary resentment of America but uncomplicated contempt and even downright disgust.

In June, the Pew Research Center’s survey of people in 37 countries found that a median of just 22% had confidence in Trump to do the right thing in foreign policy, compared to 64% during the final years of the Obama era. A striking 47% expressed a positive view of Communist China; the US was just two percentage points higher at 49%.

As disturbing as these observations are, here’s a more disturbing thought: what if the decline of US prestige and influence that has accompanied this administration’s first six months is a harbinger?

That is a more plausible prospect than you might think. After all, although Trump has contributed to the loss of America’s global standing and, consequently, a reduced ability to lead and persuade, let’s not forget the reckless dissipation of US credibility and prestige in the aftermath of the September 11 terror attacks. (Iraq, Gitmo, Abu Ghraib, Afghanistan, the GFC, Libya, Syria, Ukraine, and so on.)

Barack Obama, of course, was self-evidently far more popular than both his successor and predecessor George W. Bush. Yet even under his leadership, Washington’s demands and requests were increasingly ignored: by not just its long-time foes in Tehran and Pyongyang, but also its largest aid recipients, Cairo and Jerusalem.

On Obama’s watch, US influence had faded at global summits, too—from the G20, where the Germans rejected the US Treasury’s loose fiscal policy prescriptions in the wake of the financial crisis; to security talks, where Washington failed to reverse Russia’s incursion in Ukraine or implement Obama’s regime-change policy in Syria.

Remember, too, that Trump was elected in large part because so many ordinary Americans railed against the establishment. During last year’s primaries, whenever Trump and Democrat Bernie Sanders questioned Washington’s penchant for military intervention in the Middle East, promoting democracy across the globe and subsidising the defences of allies, they resonated with war-weary voters. The same Pew surveys that show widespread contempt for Trump’s America consistently showed a distinctly isolationist public mood in pre-Trump America. (See, for instance, this one from 2013.)

None of this is to deny America’s great strengths. It remains the world’s largest economy, the issuer of its reserve currency and its lone military superpower. Thanks to the shale gas revolution, the US is on the track to becoming more energy efficient and independent. With higher immigration and fertility rates than other developed nations, it is also in a relatively good position to deal with an ageing population.

It’s just that US prestige and influence have waned during the past 15 years and they are likely to wane in what the CNN host Fareed Zakaria calls the ‘post-America world’. What emerges in place of the kind of US global hegemony that has defined the post–Cold War world remains to be seen.

But one thing is clear: the very real tensions between Trump and the establishment are producing a foreign policy that is difficult to comprehend. That happens to perplex and even frighten US allies, such as in our region, as the University of Chicago political scientist John Mearsheimer told me recently.

That matters greatly if you want to keep in check a rising China—the only true power capable of destabilising regional order and threatening US primacy. (By themselves, Iran and Russia lack the will and capacity to overturn the balance of power in the Middle East and Europe, respectively.) If America is serious about foreign affairs in coming years, it needs a president who is thinking strategically and working closely with its allies to preserve the Asian peace and prosperity that US strategic pre-eminence has ensured for generations.

But that is not happening, because Trump is such a loose cannon and strikingly ignorant of the world—a potentially deadly combination in a crisis. What he is doing, however, is unnerving US allies in East Asia, which is no way to preserve the regional balance of power in the face of a rising China.