"What did you say?"

"I wasn't talking to you."

"Well, I wasn't talking to you!"

"Sheesh, calm down."

"I am calm!"

"Oh, right, you're calm. That's why you're screaming."

"I am not screaming! Why are you so rude? I can't believe how mean you sounded: 'I wasn't talking to you.' "

"You said the exact same thing to me!"

"I did not!"

"Yes you did, you said, 'I wasn't talking to you.' "

"Well, I wasn't! Anyway, I didn't say it in a mean way -- "

Ah, there's nothing like the smell of pyrotechnics first thing in the morning.

Strictly speaking, it was not the very first thing -- we'd all had breakfast, and most of us were now in the car, en route to schools. But the sudden eruption of conflict made it feel like the first thing; one's very skin felt sensitive and vulnerable, as though the angry words that were flying past might pierce and lodge themselves.

I pulled the car over and parked on the shoulder of the road, a thousand lectures swirling in my head. The children fell silent. A few droplets of rain smacked the front windshield. It was that kind of morning: Even the sky was teary.

"She was -- "

"He shouldn't -- "

"Shhh," I said, turning around in the driver's seat. There were noncombatants in the car, too. They looked at me.

Was I going to yell? Cry? Hand down a terrible edict?

Demand that everyone behave more kindly? Plead with the belligerent parties to forgive one another, for heaven's sake, and to knock off the bickering?

I wanted to do all these things simultaneously, to be honest, but none of them seemed to quite fit the situation. So after a moment of silence, I just pulled the car back on to the road, and we continued on our way.

It was a quiet ride after that. By the time I made the return journey to retrieve everyone at the end of the day, the incident, so far as I could tell, had either been forgotten -- or slipped into invisible dossiers that each child would be able to consult in the face of future outrages. (Remember the time when you ... ? I was so mad that day when ... !)

It sometimes feel like a handicap, not having had siblings when I was growing up. My children will occasionally point out that I simply can't understand the dynamics between them. I have no instinctive grasp of why they are compelled to compete the way they do; why infinitesimal marginal differences between portions of cake take on the magnitude of sequestration; why one child's talent in a particular area threatens any other child who might have a similar interest.

The invisible and continuous flow of rivalry, even among and between siblings who generally get along well, is a foreign thing for me. Experience has taught me something, though: Any relationship with a bit of friction only gets worse when you seal it inside a car on a rainy day.

When I mentioned this to a friend the other day, she laughed and told me a war story of her own. One rainy day, she too had to pull the car over to separate a pair of battling siblings. Her son and daughter had been pretending that they each had a candy factory, and within minutes, they were actually hitting each other in their fury and disagreement. What was the issue? Whether pretend candy could give you a pretend stomachache.

To paraphrase Clausewitz, car travel is the continuation of war by other means.

Meghan Cox Gurdon's column appears on Sunday and Thursday. She can be contacted at mgurdon@washingtonexaminer.com.