The greatest threat to both the resolve and resilience of the Western alliance in confronting the dictatorships would be the possible return of Donald J. Trump to the White House.

This would be an incomprehensible disaster for democratic support for Ukraine against Russian invasion; Taiwan against Chinese Communist aggression; and all of those threatened by potential nuclear weapons in the hands of autocrats from Pyongyang to Tehran.

For those who question this confident statement on reality, please consider the following.

Donald Trump has claimed that he would settle the Ukraine war in 24 hours.

Not my words, his.

There is only one way in which Trump could settle the Ukraine conflict, and that is by abject surrender to Vladimir Putin.

The Russians will accept nothing short of a complete surrender by Kyiv and the confirmation of their seizures of Ukrainian territory from the Donestk to Crimea.

So the carefully crafted and formidable alliance of countries, built by the Biden administration, supporting Ukrainian independence – NATO and beyond to Australia, South Korea and Japan, for example – would crumble, and the supply of both lethal and non-lethal aid to Kyiv, especially high-technology weaponry that is critical to Ukraine’s defence, would first be interrupted and then dramatically reduced.

Without US leadership and the Pentagon’s withdrawal from the military supply chain, a number of NATO members would become extremely cautious at continuing to confront the Russians.

True, NATO members such as Poland and the Baltic states would continue to back the Ukrainians.

But US aid and US determination is utterly critical to a successful Ukrainian defence of its sovereignty.

The United States remains the indispensable country, to use Madeleine Albright’s memorable phrase.

Which brings me inevitably to discuss Trump’s attitude towards US allies, as represented by his last, chaotic period in office.

Do people remember the abuse heaped upon allies such as Justin Trudeau of Canada?

Is it so difficult to recall the dismissal of vital US allies such as Germany during the Chancellorship of Angela Merkel?

Or do we simply disregard the insulting attitude that Trump displayed towards British Conservative Prime Minister Theresa May?

We need not consider the contempt which Trump is reported to have demonstrated for America’s war dead in French cemeteries during an official visit to Paris.

Or his rhetorical question about who would go to war in support of Montenegro?

Montenegro is, of course, a comparatively new member of NATO (June 2017).

And also, protected by Article 5 of the NATO Treaty, which binds all members, including the United States, to mutual support when one of their number is attacked.

It is this that has kept the Russians from launching military assaults upon the Baltic states.

It is also worth considering the number of cabinet-level officers concerned with US and global security whom Trump dismissed during his presidency.

Defense secretaries came and exited through a revolving door, including an outstanding American General in James Mattis.

Mattis was not only a formidable American General during the war in Iraq, but he was a remarkable thinker who understood the value of US allies as force multipliers. But neither his courage in action nor his impressive intellect saved him from a President who had no regard for independent views.

Trump appointed Mark Esper as Mattis’ replacement, then later fired him.

There is a significant problem facing his supporters, self-affirming in their ideological bubbles, and wanting to see Trump’s return to the White House and the power of pardon (for himself).

These days, there is almost no one in Republican ranks of any seniority likely to accept an appointment in a second Trump administration.

There will be no John Boltons or Nikki Haleys, not even a Bill Barr or a Jeff Sessions.

And inside the White House, there will be no one of the calibre of former Trump Chief of Staff, General John Kelly.

Trump has routinely given the clear impression that he prefers dictators – Vladimir Putin, Xi Jingping, Kim Jong-Un – to democratic leaders of any persuasion or nationality.

The twice impeached and thrice indicted former President would be a catastrophe back in the Oval Office.

It is to be sincerely hoped that American voters spare the world this potential outrage.