Sometimes, during family dinners, when we’re talking about the wild and fearsome events sweeping the world, I’ll look across the table to the partners of my two daughters and shiver for these young men.

I get this terrible vision of them in uniform, having to pick up a gun and fight. I’m very fond of these young men, in their mid-20s. They’re good people, decent-hearted. They love my daughters, and are working hard to forge happy lives in cruel times.

The world I’ve known since my birth has gone. My world, shaped from the 1945 peace, wasn’t perfect, far from it, but a buffer existed between us and war.

Neil Mackay predicting in 2020 that Trump wouldn’t leave office peacefully

I grew up, came to manhood and entered middle-age without the thought of having to fight ever crossing my mind. I no longer feel that’s true for today’s youth. Mine was, perhaps, the luckiest generation.

That ghost of dread in the back of my mind took on greater shape this week when Defence Secretary Grant Shapps - not a man I often accord with - spoke of the looming threat of global war.

We’re at the “dawn of a new era”, he said. The Berlin Wall is “a distant memory. We’ve come full circle, moving from a post-war to a pre-war world”. Shapps took the very words from my mouth.

“In five years,” he speculated, there could be “multiple” wars involving “Russia, China, Iran and North Korea”. I fear he’s too optimistic. Time isn’t on our side.

Nobody believed the First World War would happen, until it did, until events sped up so fast they swept a generation into the arms of death. It feels we’re there again.

Every night on our news we hear the wail of dying children, see the spectres of grieving parents wandering through bomb craters. The news is a conveyor belt of death.

That conveyor belt seems to inch us here in the once-safe and cosy West ever closer towards conflict. That’s why I shiver for those two young men.

Neil Mackay on the science of why politics attracts dangerous people

Men and women, young and old, suffer and die during war, but it’s upon young men that the worst of war falls.

And here’s the piece of grit in my brain, rubbing and scratching away at my thoughts, summoning these awful notions: if Donald Trump wins the next US election then Ukraine is defeated.

Of that, there’s no doubt. He’ll cut off military aid. It will all be over. Dictatorship will have beaten democracy. In Europe, we’ll be on our own.

Russia will begin breathing down the neck of nations like Poland - Poland for pity’s sake, Poland which burns the date "September 1939" into your brain.

China, emboldened, will turn its eyes to Taiwan. Trump may love Putin but he doesn’t love Xi Jinping.

Could we see war in Europe and the Pacific? What would that conflict be called?

You know as well as I do what history would name it. I don’t want to even utter those three words in case I tempt the fates to punish us more.

Another theatre of war already burns like hell. The Middle East. The monstrous Israel-Gaza conflict is sucking the West into military action in the Red Sea, where Houthis propped up by Iran attack shipping.

Meanwhile, Iran is striking targets in Iraq, Syria and Pakistan. I ask you: imagine this scenario with Trump in power. How would he respond to military aggression by Iran?

Europe. The Pacific. The Middle East. Those three unsayable words rear up again.

And yet, the dam wall between us and those three dreadful words - that future which none of us can truly imagine - is an 81-year-old man and his deadly ego.

There’s every chance in hell - because only Satan can be content these days - that Joe Biden loses to Trump. When African-American voters start deserting Democrats, as they’re doing now, then the wind blows bad.

The Herald: Donald Trump after speaking at a campaign event in Atkinson, New Hampshire, on TuesdayDonald Trump after speaking at a campaign event in Atkinson, New Hampshire, on Tuesday (Image: PA)

It’s now all but too late for Democrats to choose a new presidential nominee to run against Trump. Biden won’t stand down anyway.

He’s not a bad man. From a liberal European perspective, Biden seems good for America. But that’s not how Americans seem to see it. Trump is consistently ahead - albeit by small margins - in nationwide polls.

The irony for Biden is that by standing down, for a candidate with more chance of winning, he might well be protecting himself in his old age. Trump wants vengeance.

He’ll put his "enemies" in jail. He’s ready to stack the federal government with loyalists. Trump even said he’ll be “dictator”, but on “day one” only.

One day is all it takes to pass emergency powers and smother democracy. The likely chaos and political violence that will follow November’s election will provide just the grounds needed.

Then one by one little lights start going out. American leadership will disappear from the world stage. We might bridle at the thought of depending on Washington across the rest of the West, but’s that realpolitik. Nato will become hollow; democracies will dwindle.

Belgium’s Prime Minister has just warned that Europe will be “on its own” if Trump wins. We should quake at such statements. Nato gutted. Kyiv defeated. Putin like Hitler after the Sudetenland. Xi prowling the Pacific. Hell in the Middle East.

Neil Mackay on the QAnon connection to Donald Trump

I hope you understand why I look across my dinner table at those two young men whom my daughters love, and fear for them, and fear for my daughters and fear for unborn grandchildren I want to hold and kiss and love.

I fear for my wife. Shamefully, I fear for myself. We’re still young - or at least I feel it - in our early 50s, but I don’t want to enter old age in a world at war.

I’ll say it, finally. I’ll use those three words I fear to say in case I summon something unimaginable into being: I do not want to grow old during the Third World War.

Today, it’s another old man who seems to be laying the sulphurous path to this future I dread: Joe Biden.

A decent man, but a man whose ambition and pride - whose defeat by Trump - may place him in the history books as a catalyst for 21st century war.