When I was a young man, I used to respect the opinions of the old.

I figured their long years had given them great wisdom. I reasoned that a lifetime of experience had given them a maturity, a sound common sense and a powerful filter for bull that youth could only envy. In my teens and 20s I listened closely when they talked.

Not any more.

The events of this year — the Trump phenomenon, the Brexit shock — have killed that off for good.

I am watching people who grew up in the 1940s eagerly cheering for a violentthug who is openly promising retribution against his opponents and the press after he wins.

I am watching people who remembered the catastrophic costs of the Smoot-Hawley tariffs, and the Great Depression that followed, cheer for trade wars and protectionism.

I am watching people who remember Hiroshima and the Cuban missile crisis cheer for a man who speaks cavalierly of spreading, and even using, nuclear weapons.

I am watching people who lived through the Vietnam War — and in many cases fought in it — cheer a rich guy who avoided the draft in the 1960s and now tells jokes about it.

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I am watching people who lived through the Cold War cheer for a presidential candidate who is so obviously in cahoots with the Kremlin that he cannot bring himself to criticize Vladimir Putin, even when doing so would help his campaign.

I am even watching people who watched the 20th century’s “long, twilight struggle” for democracy around the world now boast about throwing their own vote away.

Above all, I am watching armies of elderly people decide to impose terrible risks, without shame, on their own children and grandchildren. Some of Donald Trump’s strongest support comes from the over-65s. He enjoys a significant lead among older voters. If the election is close, they’ll put him in the White House.

But they are not the ones who will bear the cost if he becomes president and does his worst. They have their investments, their homes, and their Social Security payments. They enjoy the security of Medicare, the world’s biggest socialized medicine program.

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If there is a war, they will not have to fight. If there is a depression, they will not lose their jobs. If he scraps universal health care, they won’t lose their coverage. And if this unbalanced man leads to catastrophe, as he might, they will not lose the chance of a long and happy life. They’ve already had most of theirs. Their future expectancy is counted more in years than in decades.

Those who will pay the price are the young and the middle-aged. And they don’t want it. Those in their 20s, 30s and 40s oppose Donald Trump by huge margins.

The issue with Donald Trump is not what is certain, but what is at risk. He is quite obviously an angry, unbalanced, petulant, vengeful, egotistical and ignorant man. He boasts about “getting even” with anyone who’s crossed him. He wakes up at 3 a.m. and lashes out in anger at his enemies. If he can’t stop himself from hitting out at Gold Star families and retired beauty queens, how will he react to a provocation by North Korea?

“ No wonder so many financial con artists target the old. They aren’t as sharp as they were. ”

There is a non-negligible risk that he will cause a war, an economic collapse, a political crisis, or even a nuclear confrontation. How grandparents can take such gambles with their own children or grandchildren’s lives is beyond me. It is a total disgrace. They should be ashamed of themselves.

No wonder so many financial con artists target the old. They aren’t as sharp as they were. They aren’t as sharp as they think they are. They rely on too many unreliable memories. And apparently they are amazingly self-centered.

Earlier this summer I had an argument in Britain with relatives in their mid-80s. They planned to vote for Brexit — even though, they cheerfully admitted, they didn’t expect to be around to see the long-term consequences.

I asked: “Doesn’t it bother you that all the young people, who really will have to live with the consequences, are against Brexit?”

It didn’t. “We know better,” they said.

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Since then the British pound has collapsed by a staggering 20%. British real-estate stocks are at crisis levels. Britain narrowly avoided a major post-Brexit political crisis. The new government is fighting to keep major employers in the country. The U.K. is almost certain to lose access to Europe’s single market — and only the oil slump is stopping the Scots, for now, from trying again to secede.

My point wasn’t that they should have voted for “Remain.” It’s that they shouldn’t have voted at all. They should have left this decision to the younger generation. There was a positive case for Brexit. But it was a case that should have been left to those who would pay the costs.

How ironic that this year is the 100th anniversary of the Battle of the Somme in the World War I. Never before have so many older people sacrificed so many young people for their own vanity. They spent four years trying to fight machine gun bullets with young men’s chests. When it was over, tens of millions of younger people were dead, and the world was worse than before. And the people who paid the least price? The older men and women who started it.

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