Donald Trump’s self-reverential style of personalised, fly-by-the-seat-of-your-pants diplomacy just crashed and burned in Hanoi. It is fitting, perhaps, that Vietnam – scene of past American humiliations – was the setting for the blunderer-in-chief’s greatest flop. Trump tried to wing it in nuclear talks with North Korea’s more canny leader, Kim Jong-un, and got what he deserved: precisely nothing. The summit, like last year’s effort in Singapore, was a Trump vanity project – and proved a labour in vain.

In principle just about everybody, including close neighbours South Korea, China and Russia, would like to see North Korea’s nuclear arsenal brought under international supervision, and preferably eliminated altogether. To make such a mess of things, given this exceptional consensus, is a true measure of Trump’s incomparable incompetence. Yet this is barely a surprise. It is entirely of a piece with his amateurish approach to key foreign policy challenges the world over.

The Hanoi summit collapse reaffirms Trump's amateur hour in diplomacy | Michael H Fuchs Read more

Given the lack of progress in preparatory talks, it was a wonder the US went ahead with the summit at all. Pre-meeting media reports, quoting senior officials, suggested growing concern in Washington that Kim had no intention of complying with the core demand for denuclearisation, or of fully listing his nuclear facilities. As it turns out, they were right. But Trump insisted on having his moment.

Trump’s advisers were also worried he would make reckless, unilateral concessions, as he did last year when he suddenly cancelled US-South Korean military exercises. Before the summit, and again after it, Trump said he would be content if North Korea merely continued its moratorium on missile and bomb testing.

Talk about giving away the shop. For a man who prides himself on driving a hard bargain, it was remarkably naive.

In truth, Trump made the summit all about him. His main objective was to enhance the delusional image he has of himself as global peacemaker. He firmly believes he deserves the Nobel peace prize. In this year’s State of the Union address he loudly praised himself for saving millions of lives by averting a “major war” in Korea. If such a war was ever a real prospect, it was largely because of Trump’s panicky response to Kim’s 2017 long-range ballistic missile tests. He was out of his depth then, and was so again in Hanoi.

Play Video 1:31 Trump on Kim Jong-un talks: 'Sometimes you have to walk' – video

The summit failure is a big setback for South Korea’s president, Moon Jae-in, who, notwithstanding Trump’s shenanigans, has worked hard to build bridges to the North. But Kim will be more than happy. Thanks to Trump, the process of his international rehabilitation continues – a political coming-out parade that began in Singapore. His standing, at home and abroad, has been further enhanced at no political cost.

While Kim basks in Trump’s praise as a “great leader” and “friend”, an outmanoeuvred, out-thought US president has been left to trail home with nothing to show. Kim will not worry, for example, that an always symbolic end to the 1950-53 Korean war was not agreed. But he will be delighted the risk of precipitate American military action has further receded. Meanwhile, he can continue his covert nuclear build-up.

On the advice of John Bolton, his national security adviser, Trump resisted Kim’s demand that all US sanctions be lifted. But his agreement to continue lower-level bilateral talks – and the de facto “normalisation” of US-North Korea relations that implies – means China, Russia and other countries that are already bypassing UN-led sanctions on Pyongyang will feel free to go further.

The art of the no deal: how Trump and Kim misread each other | Julian Borger Read more

Trump’s inability to lay a diplomatic glove on Kim in the Hanoi rematch also means North Korea’s dictator has again emerged unscathed over his regime’s appalling human rights abuses. When it suits him, Trump is quick to use human rights as a stick to beat governments in Iran or Venezuela. In his 2018 State of the Union address, before he got chummy with Kim, Trump declared: “No regime has oppressed its own citizens more totally or brutally than the cruel dictatorship in North Korea.”

Trump was right, or at least his speechwriter was. Kim presides over a gulag of forced labour camps of appalling inhumanity. North Koreans are subject to arbitrary arrest, torture and indefinite incarceration without trial. The regime’s corrupt and incompetent economic management has caused mass starvation.

Yet in Hanoi, his confected fury forgotten, Trump made no mention of these ongoing abuses, nor did he try to do anything to curb them. When asked about an American student, Otto Warmbier, who was mistreated in a North Korean prison and later died, he absolved Kim of responsibility. Kim, he said, “felt badly” but “didn’t know about it”. It was another Khashoggi moment – and similarly stomach-turning.

Play Video 1:31 Otto Warmbier: Trump says he believes Kim Jong-un was unaware of torture - video

Trumps’s rightwing nationalistic instincts; his coddling of dictators; his cultivated ignorance of complex, sensitive international problems; and his image-driven refusal to look beyond the next news cycle, have become fixed features of his foreign policy approach.

It is this approach that has given us the appeasement of Vladimir Putin’s Russia at Europe’s expense, cut-and-run troop withdrawals from Syria and Afghanistan, a dangerously obsessive vendetta against Iran, an unconscionable betrayal of the Palestinians, and a chaotic attempt to impose regime change on Venezuela.

Trump’s Hanoi bumbling follows a set pattern of unfitness. It is the very opposite of leadership. And it can only give comfort to the enemy.

• Simon Tisdall is a foreign affairs commentator.