“Give peace a chance” was what they said back in the Vietnam War era of the 1960s.

And what reasonable person could argue with it? War is something to avoid — unless the alternative is even worse.

Those thoughts are prompted by two events this weekend.

First — and for the first time — I went back to my old high school for commencement.

At the alumni luncheon, a graduating senior gave a speech about the most important things he had learned at the school. His main point was that life will knock us down over and over. Sometimes, each of us will feel utterly hopeless and defeated. In those moments, we must get up and go on. Get up and go on.

It was an impressive speech by an impressive person. Afterward, I shook his hand and told him “¡Buenísimo! ¡Buena suerte!” (Outstanding! Good luck!) because though he had only a slight accent, he came from Mexico City.

And where will he attend college?

West Point: that is, the United States Military Academy at West Point. He will graduate as an officer in the U.S. Army.

The second event was that the U.S. Army posted a Memorial Day question on Twitter:

“How has [military service] impacted you?”

Many of the replies were heartbreaking. Some people told of family members who were wounded, killed, or had psychological problems. Others told of bad experiences during their own military service.

Even though most veterans (including three members of my family*) are proud of their service, there’s no denying the horrors of war. When possible, it must be avoided. When unavoidable, it must be won.

If exemplary people like my school’s luncheon speaker are to be put in harm’s way, it cannot be simply to “busy giddy minds with foreign quarrels.” We must not get involved in other people’s wars just because we can. War is serious. It is neither a punchline nor a prop for political campaigns.

I’ll give the last word to John Stuart Mill, the British economist and philosopher:

“War is an ugly thing, but not the ugliest of things: the decayed and degraded state of moral and patriotic feeling which thinks nothing worth a war, is worse.

A man who has nothing which he is willing to fight for, nothing which he cares more about than he does about his personal safety, is a miserable creature, who has no chance of being free, unless made and kept so by the exertions of better men than himself.”

* I tried to get in, but the military wouldn’t take me because my eyesight was so bad (20/600 before Lasik).

Check out my new book Why Sane People Believe Crazy Things: How Belief Can Help or Hurt Social Peace. Kirkus Reviews called it an “impressively nuanced analysis.”