You don’t have to have been born on the road between Harry Truman’s house and Dwight Eisenhower’s to have some appreciation for the history of the last century. But it probably helps.

The fact that the Current Occupant is on his way to Europe to hobnob with his fellow wizards comes as His Accidency is again showing that he doesn’t have a clue what the North Atlantic Treaty Organization is, what is it for and why we owe it a great deal of respect.

The president is determined to be the skunk at this garden party, tweeting out baseless attacks on the alliance that kept the peace and held the line in Europe since 1945. He keeps saying things that only make sense if you think that NATO is branch of the United States Department of Defense and that all the member nations whose national security is bolstered by that treaty are supposed to be paying us rent. More rent.

Which might make sense if you spent your life as a landlord and hotel developer.

But NATO is an alliance of nations — equals in sovereignty and responsibilities even if vastly unequal in strength and size of economy. Truman was president when we joined and Ike was its first commander.

The linchpin of the North Atlantic Treaty is Article 5:

The Parties agree that an armed attack against one or more of them in Europe or North America shall be considered an attack against them all and consequently they agree that, if such an armed attack occurs, each of them, in exercise of the right of individual or collective self-defence recognised by Article 51 of the Charter of the United Nations, will assist the Party or Parties so attacked by taking forthwith, individually and in concert with the other Parties, such action as it deems necessary, including the use of armed force, to restore and maintain the security of the North Atlantic area.

(Note the Brit/Canadian spelling of words like “defence” and “recognised.” They apparently outnumbered us on the drafting committee.)

When this was agreed to, the obvious threat was that the Soviet Union, you remember them, would attack, probably, Germany, and all the other nations would be called upon to repulse the invasion. That’s why we always had tons of troops and trucks and tanks and helicopters in Germany. To make keeping that promise easier.

In all those years, though, Article 5 was invoked exactly once. And it wasn’t an attack in Europe by the Ruskies. It was the terrorist attacks on the United States on Sept. 11, 2001. When we went after al Qaida and its hosts, the Taliban government of Afghanistan, we didn’t go alone.

Canadians were there. I know because I saw a CBC report with a general drinking out of a Tim Hortons cup.

Italy sent its only aircraft carrier battle group. There were Poles and Belgians and Germans and French and Czechs.

The British were in deep with us. They not only sent marines and soldiers and planes and helicopters, they sent Capt. Harry Wales — aka Prince Harry.

Harry flew Apache helicopters, which is dangerous even when people aren’t shooting at you. He was there for four months, and would have stayed longer if some English newspaper hadn’t outed his location and made it too dangerous — for him and those around him — for him to stay.

So, when Harry’s life returned to the posh and the royal, that military uniform he wore to his wedding was not a prop. It was fully earned.

Britain's Prince Harry, left, and Meghan Markle wave from a carriage after their wedding ceremony at St. George's Chapel in Windsor Castle in Windsor, near London, England, Saturday, May 19, 2018. (AP Photo/Kirsty Wigglesworth, pool)

Unlike some other people’s positions and honors and pomp. It is notable that, as the president’s visit to the U.K. also nears, one of the most requested/downloaded/streamed songs there is Green Day’s “American Idiot.”

Maybe the president’s good friend, the leaders of the nation that NATO was originally set up to counter, can offer him some consolation. Because America’s friends won’t.

George Pyle, the editorial page editor of The Salt Lake Tribune, used to be bothered by the fact that he was older than the president of the United States. Now he is smarter. And that’s much worse.