For those who have been alarmed by Donald Trump’s retreat from traditional American values, there were reassuring moments on Tuesday in his first address to the United Nations General Assembly.

Trump rightly and scathingly attacked regimes that deprive their own people of liberty, such as those in North Korea and Venezuela, but he did not limit his attacks to easy targets. He criticised “authoritarian powers” that “seek to collapse the values, the systems and alliances that prevented conflict and tilted the world towards freedom since [the Second World War]”.

Specifically, he came to the defence of the sovereignty of Ukraine and the South China Sea — that is, in the face of challenges from Russia and China. He said the United States expected all nations “to respect the interests of their own people” and the United Nations to be “a much more accountable and effective advocate for human dignity and freedom around the world”.

These represent a heartening endorsement of enduring American goals.

Less reassuring were the President’s schoolboy taunts of “Rocket Man”, his sobriquet for North Korean dictator Kim Jong Un, and his threats, if the US is “forced to defend itself or its allies ... to totally destroy North Korea”.

The leader of a powerful nation makes himself sound simultaneously weak and bellicose with such bluster.

Then, somewhere in between, there was Trump’s repeated emphasis on sovereignty. He talked often and admiringly of “strong sovereign nations” and “strong and independent nations”.

We agree that “the nation state remains the best vehicle for elevating the human condition”, but there was something discordant in using the United Nations podium to proclaim the virtue, essentially, of national selfishness over international co-operation and multilateral organisation.

No doubt, Xi Jinping and Vladimir Putin, the presidents of China and Russia respectively, will welcome this aspect of Trump’s address. They, too, have insisted on the unassailable “sovereignty” of their formidable states and demanded that others not lecture them about values such as democracy and human rights, which they fear and abhor.

Putin once rolled out a concept he called “sovereign democracy”, which turned out to be nothing more than a cover for eventually crushing Russia’s nascent democracy.

Indeed, Trump seemed to repudiate his own advocacy for human dignity and freedom when he said that “we do not expect diverse countries to share the same cultures, traditions or even systems of government” — as if democracy should be optional under the UN Charter.

Trump cast the Polish, French and British resistance to Nazi dictatorship as motivated by “patriotism” for the “nations that they loved”.

This is a superficial rendering of what was in fact an existential drive to save democratic and free societies from a genocidal steamroller. The US, too, fought and sacrificed for these hallowed principles. And when the war ended, the UN was created to protect these values — the charter says to protect “faith in fundamental human rights, in the dignity and worth of the human person” — and not just to provide a new system for nation states to get along.