PRESIDENT DONALD TRUMP (Gage Simon photo).

As he exercises his Putin-given right as president to lay waste to the United States, it turns out that Donald Trump can really draw from only a very few weapons in his quiver as he causes all the traditional allies to quiver. When all else fails, he pulls out his favorite economy-piercing arrow: the tariff.

Got a problem with immigration? Shoot an escalating tariff at all things Mexico. Never mind that Mexico is the United States’ third-largest trading partner, after Canada and China, where he has also aimed the tariff arrows. In the case of Mexico, because of the North American free trade agreement, the borders have little meaning when it comes to commerce.

Crops move north constantly, a regular flow that keeps prices down. In manufacturing, assembly parts shuttle back and forth incessantly, so the accumulating tariffs would add to the price of just about every consumer good that we purchase. The resulting downturn would mean American layoffs, lots of them. Mexicans also would be put out of work.

That might be a perverse incentive for added numbers of them to try to sneak into the United States. But when the Trumpster gets an idea in his head, particularly one whispered by his anti-immigration fanatic adviser Stephen Miller, it doesn’t matter whether the reaction is bipartisan or not, as it is in this case.

He also doesn’t need the approval of his other aides, who oppose the idea as needlessly destructive to the economy; Trump fires his tariffs willy-nilly at any country that dares to irritate him. As for those nations where trade is not a reality, like Iran or North Korea, he automatically turns to sanctions.

Or blusters about sanctions, otherwise known as BS. Between sanctions and tariffs, the man clearly is an S&T fetishist. Usually, he backs down, leaving the unmistakable impression that he’s constantly bluffing. On his latest threats against Mexico, for instance, he has allowed for a couple of weeks before he’ll fire his arrows into the heart of both countries’ economies.

But in his mind, the intimidation tactic will work. If it doesn’t, then it could wreak financial havoc. Now he’s had tea with the queen of England. With his reputation for breaking china wherever he goes, one can’t help but wonder if the royals served his tea in plastic foam cups. His entire excursion is as meaningful as his golfing trip to Japan was, although even there he left some hard feelings.

This controversy is most notable for its pettiness. He has heavy-handedly made his contempt for John McCain well-known, even after Sen. McCain died. It reached a low in Japan. POTUS, perhaps smarting from the criticism that he was playing overseas during Memorial Day weekend, scheduled a shipboard meeting with Navy crewmembers aboard the USS Wasp. There were none invited from the nearby destroyer USS John McCain.

Never heard of the USS John McCain? Perhaps that’s because someone in the White House ordered the vessel to cover its name with tarpaulin. How pathetic. Once this was discovered, the president, his acting defense secretary and anyone in authority denied any knowledge. But besides the measly weasliness of this controversy, it was totally unnecessary: If President Trump wants to take a shot at the McCains, all he needs to do is level tariffs on them.

Bob Franken is an Emmy Award-winning reporter who covered Washington for more than 20 years with CNN.