US President Donald Trump takes the oath of office with his wife Melania and son Barron at his side, during his inauguration at the US Capitol in Washington, US, January 20, 2017. [Photo/Agencies]

The United States' foreign friends and partners had hoped that as the new US President, Donald Trump might temper the aggressive rhetoric he employed when campaigning, and that somehow, as one commentator put it, "the trailer would turn out to be worse than the movie".

Many must have been disappointed therefore by an inaugural speech variously described as divisive, isolationist and pessimistic in headlines at home and across the world.

Setting aside the tradition of inaugural presidential appeals to hope and unity, Donald Trump presented a dystopian vision of the US in which, amid widespread poverty and crime, there are "rusted-out factories scattered like tombstones across the landscape of our nation."

He left no doubt about who was responsible for this "carnage": it was the fault of foreigners who had stolen jobs from Americans.

The new president did not actually name these aggressors. But echoing accusations he leveled at China during his campaign, and since, he warned: "We must protect our borders from the ravages of other countries making our products, stealing our companies, and destroying our jobs."

There was also little comfort for the US' closest allies in Trump's choice of "America First" as the keynote slogan of his speech. For European countries, the phrase echoes the isolationism of the 1940s when the America First Committee campaigned to keep the US out of World War II, even at the risk of abandoning Europe to the Nazis.

His inauguration took place against the backdrop of anti-Trump demonstrations on the streets of Washington, and riot police had to use tear gas and stun grenades to disperse the crowds. More than 200 people were arrested.

Organizers of Saturday's Washington Women's March, part of worldwide anti-Trump demonstrations, were predicting that as many people would turn out as attended the inauguration the previous day.

Trump has entered the White House with the lowest approval ratings of any modern US president, which was reflected in the lower-than-predicted turnout along the Washington Mall on Friday.

Commentators had theorized that, once in office, Trump might use his first speech to strike a more emollient tone. That was not to be, however.

"It was like he was still in campaign mode," was a typical response from one US citizen interviewed.

It was left to elsewhere in the new administration to stretch a hand of friendship to the rest of the world. Retired General James Mattis, sworn in on Friday as secretary of defense, said: "Recognizing that no nation is secure without friends, we will work with the State Department to strengthen our alliances."

Mattis thereby struck a softer note than Trump, who had criticized NATO, questioned the future of the European Union and insulted Germany in the days before his inauguration.

The enduring abrasiveness of Trump gives no real clue as to how his presidency will tackle the real challenges facing the country, and he has yet to produce a coherent doctrine of foreign relations.

But how long can the world maintain this wait-and-see attitude toward a man who now occupies what is routinely described as the most powerful position in the world?

The US' international partners have their own challenges to deal with－on trade, on security, on climate change, on combating Islamic extremism and on reinforcing existing alliances, particularly the EU.

The US has for three-quarters of a century－since an unprovoked attack by Japan forced it to abandon America First isolationism－played a central role in such global issues.

Now a new president is signaling an inward-looking retreat. But no one yet quite knows what that will involve, or how far the checks and balances of the US system will constrain him from doing anything rash.

The writer is a senior media consultant to China Daily UK.