If President Trump called off an Iranian attack in order to save innocent civilians, he deserves praise. Render to God what is God’s, and to Caesar what is Caesar’s. But, as a Wall Street Journal editorial emphasized, there is something off in this story (“Iran Calls Trump’s Bluff,” June 21, 2019):

It’s important to understand how extraordinary this is. The Commander in Chief ordered ships and planes into battle but recalled them because he hadn’t asked in advance what the damage and casualties might be? While the planes were in the air, he asked, oh, by the way? This is hard to take at face value. …

More likely, he changed his mind because he had second thoughts about the military and political consequences of engaging in a conflict he promised as a candidate to avoid.

Strategic threats have long been modeled with the help of game theory. A classic is economist Thomas Schelling’s 1960 book, The Strategy of Conflict (Harvard University Press). In game-theoretic terms, if you play a chicken game without having credibly committed to staying in the middle of the road, expect to lose one way or another: the other player is likely not to swerve; and you will have to swerve yourself, or else a crash will occur.  As the Journal puts it,

This is the reality of geopolitics in which credibility is crucial to deterrence. The more that adversaries think Mr. Trump’s threats of force aren’t credible, the more they will seek to exploit that knowledge.

A second explanation of Mr. Trump volte-face in the drone affair, then, is that he just discovered he is not the only bully on the world scene; and that tussles of war between states are not like rivalry in the New York real estate market. As most Americans may not be eager for another foreign war, he decided to call off the retaliatory attack.

Other questions must be asked, of course. Would this be a just war? Should the president have the power to start it? Why did he pull out of the Iranian nuclear accord? Wasn’t the accord a good way to keep the Iranian government under some control while minimizing the risk of war? Aren’t the silent threats of diplomacy better than the open threats of war?

In a public-choice perspective, it is quite possible that the electorate, or the third of registered voters who voted for Mr. Trump, want to both avoid war and put foreigners in their place: A and non-A. Such incoherence is well known in voting processes (see my post “Condorcet’s Brexit,” April 9, 2019). It is compounded by the incoherence of Mr. Trump himself, who lacks any philosophical or economic compass. His foreign policy looks as rational as his trade policy. The Journal editorialist is slightly more charitable:

The great weakness of Donald Trump’s foreign policy is its volatility. He is unpredictable to a fault. He has doubted his own Venezuela policy from the first week he signed off on it. He called Kim Jong Un crazy but now says he’s a swell guy. He signed a trade deal with Mexico then threatened it with new tariffs.

So another explanation of Mr. Trump’s volte-face is that he is inconsistent and incoherent.

I had written this post and scheduled it for publication when new information emerged in a Saturday night Journal story (“Trump Bucked National-Security Aides on Proposed Iran Attack,” June 22, 2019):

In private conversations Friday, Mr. Trump reveled in his judgment, certain about his decision to call off the attacks while speaking of his administration as if removed from the center of it.

“These people want to push us into a war, and it’s so disgusting,” Mr. Trump told one confidant about his own inner circle of advisers. “We don’t need any more wars.”

It was unclear whether the division within the team—which includes Mr. Trump’s third national-security adviser, second secretary of state and third official in charge of the Defense Department—would heal or continue to fester.

This would bring grist to the mill of those who believe that Mr. Trump has suddenly seen the light and changed his mind, perhaps moved by the possible loss of civilian lives in Iran. But the new sanctions that he is considering against Iran may also cost lives there, besides of course using Americans (and Europeans) as pawns to be prosecuted if they trade with Iranians. I would guess that the hypotheses of the bully’s retreat and general incoherence better explain Mr. Trump behavior.

We might consider another hypothesis: the president’s sort of autism (I am playing the behavioral economist here!) or at least his ignorance regarding what is happening in the world, how things fit in time and space.

Perhaps a presidential tweet will soon help us discriminate between these or other explanatory hypotheses.