Donald Trump’s sudden embrace this week of a nuclear arms race — and his staff’s scramble to minimize the fallout — underscored an emerging modus operandi for the president-elect: governance by chaos.

Since winning the election, Trump has seemed to revel in tossing firecrackers in all directions, often using Twitter to offer brief but provocative pronouncements on foreign and domestic policies alike — and leaving it to others to flesh out his true intentions.

In the past week alone, Trump has publicly pitted two military contractors against one another, sowed confusion about the scope of his proposed ban on foreign Muslims and needled China following its seizure of a U.S. underwater drone.

But nothing has created more consternation for many foreign policy experts than Trump’s assertion on Twitter Thursday that the country should “greatly strengthen and expand” its nuclear capability.

On Friday, after his staff had tried to temper his comments, Trump doubled down — telling a television talk show host that in an arms race against any competitor, the United States would “outmatch them at every pass.”

Trump has pledged to shake up both Washington and the world order, and boosters argue that a degree of unpredictability can be useful, particularly when it comes to foreign policy. But the mixed messages and erratic nature of his pronouncements have alarmed even some Republicans, who say it’s important to know how seriously to take the leader of the free world.

“We’re just operating in this world where you cannot believe the things he says,” said Eliot Cohen, a foreign policy expert and former George W. Bush administration official at the State Department. “It will have large consequences for our allies and our adversaries, and it’s going to greatly magnify the danger of miscalculation by all kinds of people.”

Trump’s team has struggled with the new resonance that becoming president-elect has given Trump’s Twitter habit. They have repeatedly said that his statements on social media do not necessarily reflect his official policy and have at times sought to play down the import of his actions.

But Trump supporters say the rest of Washington is going to have to get used to his more freewheeling style.

David Fuller's view

President-elect Trump has had a flying start a month before he will be sworn in as President.  He deserves credit for assembling a heavyweight team of highly successful business leaders to help him re-energise the US economy.  Wall Street celebrated his election with new all-time highs. 

That’s the good news.  The bad news may start with an excessive number of tweets, which do not add to his credibility.  In fact, they can make him look unstable. 

If Trump wants to be a great president, he could start by emulating Theodore Roosevelt, commencing with: “Speak softly and carry a big stick”.  Here are some more excellent quotes from President Roosevelt.