President Trump is in the middle of a trip to Europe whose stops include NATO, Great Britain, golf at Trumpa Scotia, and a Helsinki summit wth Putin — or, as an “Esquire” wag has it, his annual performance review.

Many of us find Trump alarming enough domestically, but even more so when he ventures abroad. Why? It took me awhile to analyze the source of the weird, queasy, familiar feeling of impeding doom such junkets inspire. But then it became obvious.

Trump’s behavior is that of a poorly brought up child, one whose mother never taught him to behave. That sort of kid is bad enough at home, but let loose on the world is a constant source of worry since he is likely to bring such disgrace upon the whole family that it may never live it down.

It’s possible that this worry about appearance is a middle-class thing. The lower classes often behave as if they can’t afford manners or regard them as an affectation, a waste of time. “Grub first, then ethics,” says a character from Brecht. Oddly, spoiled rich children are just as likely to transgress because they think the rules don’t apply to them. Trump plainly shares that view.

Did anyone ever teach him to treat women with respect, for instance? There’s no evidence to suggest it. Imagine him holding a door for a lady, or a chair. A whole lot of tabloid headlines, locker room boasts, lawsuits and MeToo victims show he is an adolescent pig who never got a talking to.

As kids, we are all taught endlessly not to lie, cheat or steal. Trump has made a career of such behavior and has put his name on ghostwritten books boasting of it. We are also admonished by father, mother, teacher, preacher to care for those less fortunate than ourselves. Trump has no philanthropic endeavors associated with his facade of wealth, even illegally using his trust as a slush fund.

As president, he has pretended to care for working people, but has set out to cut funding for programs to help the poor, has separated asylum seekers from their children just to watch them cry, mocked the disabled and dying, reveled in the misery of the disadvantaged, encouraged discrimination against minorities, and sought to deprive millions of healthcare.

We are told not to take credit we don’t deserve, but Trump not only takes credit for the work of others — as when he cribs his Supreme Court picks from the Federalist Social and Heritage Foundation — but he takes credit for imaginary things — biggest inaugural crowd ever, nukes in the hands of North Korea? Solved.

We are also told repeatedly to do our homework, to be prepared, but Trump is allergic to planning and study. He prefers to wing it, ad lib, trust his gut. He gets dubious information from like-minded friends, and copies his answers from the paper of the Fox News kid.

We are also repeatedly taught to be careful not to break things we can’t fix, but Trump thinks nothing of busting the budget, creating huge deficits, degrading the environment, shattering long-standing alliances and shredding trade agreements.

Children are also warned constantly not to hang around with the bad boys. Trump, however, yearns to be the leader of the pack. He has surrounded himself with troublemakers and thugs from an early age and as businessman, and president has empowered them — Roy Cohen, mobsters, Michael Cohen, Scott Pruitt, Ryan Zinke, Paul Manafort, Wilbur Ross, Tom Price. And when Tump leaves home he prefers the worst company he can find — Erdogan, Duterte, Kim Jong Un, Vladimir Putin. He wants badly to be a part of the gang and beat-up on the well-behaved goody goody grown-ups.

We all know we hold our breath when our kids pay visits to other people’s homes, go on field trips, or take part in group activities. We have gone hoarse admonishing them to watch their manners, be polite, play nicely wth others, learn to share, and not bring disgrace on their parents, their town, their team, or their country, a shame that they will never live down.

But Trump habitually insults his hosts, pushes others aside to hog the limelight, insists on his way or the highway, loves to dominate the conversation, has no interest in hearing the other guy’s opinion, never waits his turn, talks trash, and if he doesn’t get his way threatens to take his ball and go home. And, of course, he has no respect for girls trying to play a man’s game — Angela and Theresa, this means you.

Trump was obviously never told that, if you re lucky enough to be invited to the grown-ups table at the countries’ club, learn the rules, avoid insulting the members or telling them how to run their own business or generally act the bully. After all, the club was created to keep the bully’s in their place and to provide a safe place for the members to meet.

This might be funny if the spoiled child was still just a serial bankrupt, real estate heir and TV clown, but what’s now at stake is thermonuclear war, trade wars, the survival of democracy, the economic well-being of the world, the air we breath, the water we drink, the earth we call home, and the country we love.

So, grow up, Mr. President, mind your manners, listen to your elders, learn to play with others, and quit idolizing the bad boys. They aren’t your friends, and don’t want you in their club.