A former US state department adviser to five previous American presidents says Donald Trump’s narcissistic unilateralism is doing Vladimir Putin’s work for him by widening the fissure between the US and Europe over climate change, Iran, Brexit and Nato.

The former adviser, William Burns, said on Wednesday that the corrosive damage to the transatlantic relationships might never be repaired, and described Trump being uninterested in those alliances at a time when China was “rising’” and Russia “resurging”, as criminal.

He also predicted a post-Brexit Anglo-American relationship would be less special since part of Britain’s relationship with America was “built on its relationship with the continent”. The UK should not think a US trade deal would be anything but complicated, he said, adding: “Any trade deal requires some very difficult choices for the UK especially when you do not have the leverage of the European Union.”

Burns, a former ambassador to Russia as well as state department adviser to both Bush presidencies and to Barack Obama, is widely seen as the most respected American career diplomat of the last 30 years.

He said the “uncertainty and lack of faith in America’s leadership comes at a moment of profound transformation on the international landscape”.

He added: “It is not as though the world is going to sit by while we renew ourselves in Washington. Allies are beginning to lose faith and hedge, our adversaries are starting to take advantage. The institutions that we worked so hard to build – and I know as well as anyone are in desperate need of modernisation – are beginning to teeter. So I worry some of that damage and corrosion is not going to be undone especially if this is not four years but eight years.”

He took as an example the Trump administration seeing “Brexit through the prism of a number of illusions”.

He said: “[There is] a sense that the European Union is not so important, that the muscular unilateralism that has infused a lot of Trump foreign policy, works. But the cheerleading for Brexit we have heard from [him] just misreads one of the biggest assets the US has at a moment when the international landscape is in a process of transformation and is much more competitive.

“One of the strengths the US can draw on is the alliances and the coalitions it can mobilise. That is what sets us apart from lonelier powers like Russia and China. But there is a tendency in Washington to see those alliances as constraints rather than assets.” Trump, he said, saw Nato not as an alliance based on values but as a protection racket.

Burns, in the UK to promote his book The Back Channel, called himself a card-carrying member of the Washington establishment. He has, however, specialised in a soft-spoken, often humble, rationality, that has made him the doyen of diplomats across much of the globe.

He played a key role in secretly negotiating the Iran nuclear deal finally signed in 2015, and has expressed concern that Washington is reaching for militaristic solutions in Iran as it did with Iraq.

He has described as very short-sighted America’s use of secondary sanctions to prevent Europeans trading with Iran, pointing to warnings by Germany and France that they must respond by building European economic sovereignty independently of the US. “It may not happen overnight in five years’ time, it may not happen in 10 years’ time, [but] a lot of countries, including our allies, will have taken steps to reduce their vulnerability to the US financial system.”

The Iranian leadership, he assessed, was “trying to wait out this administration”. He said: “They think cold-bloodedly, after years of trying to isolate Iran, we have managed to isolate ourselves by pulling out of the deal.”

The US unilateral imposition of sanctions had done a lot of damage to an already badly mismanaged economy, he said. He sensed the US purpose was not to achieve a better nuclear deal but instead find capitulation or implosion. “Although there is pressure, I do not think this strategy is going to produce either of these outcomes.”

In the meantime, “a lot of collateral damage” could happen. “We are going to widen the fissure between the US and Europe, and in a sense do Putin’s work for him. Second, we run the risk of an inadvertent collision with the Iranians. Look at the crowded and combustible spaces in Syria, Yemen and the Gulf itself, and there are some in the US administration where you hear the false echoes that produced the Iraq war.”

A more fruitful course, he says, would have been to build on the nuclear deal that he accepts is not perfect, but instead removed one layer of risk. “In diplomacy, perfect is rarely on the menu,” he says.

He also expressed frustration that Trump had not been more willing “to be very honest and push back against Saudi Arabia in cases of internal over-reach, such as the horrific murder of the Saudi dissident Jamal Khashoggi in Istanbul, or of external over-reach”. He described the war in Yemen as “not only a humanitarian catastrophe but a strategic catastrophe for Saudi Arabia”.

As head of the Near Middle East section of the US state department in 2002, Burns played a rearguard, and fruitless, role trying to persuade George W Bush of the “recklessly rosy” assumptions underlying the Iraq invasion, including sending a eerily accurate memo of the possible post-invasion disorder entitled the Perfect Storm. He said he had asked himself the question many times, but even now could not judge whether Bush would have pulled back if the UK under Tony Blair had at the last minute decided not to join the attack on Saddam Hussein.

“If there was any friend, ally or external force, Britain had to have had more influence than anyone else. But it is important not to underestimate the sense of mission that the president had in the wake of 9/11 that the priority was going to be prevention.”

In the wake of Iraq and other foreign policy reverses, the task of any successor to Trump would be to heal and to govern. Trump “did not invent the disconnect between people like me in the Washington establishment and lots of American citizens [who] feel that the establishment that has let them down”. Trump, however, had accelerated it. “He is a master of playing on people’s fears and anxieties, and a sense of the other, and you got the impression that Brexiteers did the same thing here. Like Trump they did not pay a whole lot of attention to the economic or practical consequences.”