A sample of one proves nothing, but it can at least fail to disprove some theory and new raise questions. A fascinating but terrible Wall Street Journal report tells the story of Daniel Swift, a Navy SEAL who had deserted and died fighting in Ukraine earlier this year (“‘War Is Fun’: The Navy SEAL Who Went to Ukraine Because He Couldn’t Stop Fighting,” May 12, 2023).

After deployments in Afghanistan, Iraq, and Yemen, Swift was not able to adapt to ordinary social life. “War is fun,” said a US Army veteran. In many ways, the story of Mr. Swift is consistent with the economic way of looking at individual choices including those involving violence.

UCLA economist Jack Hirshleifer reminded us that there are two broad options in life: peaceful cooperation or violence. Swift’s life story confirms that some individuals have a comparative advantage in violence, whether it is biologically innate or acquired or a combination of both. A comparative advantage describes what one can do comparatively better than some others and thus specialize in. Adam Smith believed that comparative advantage was acquired: “The difference between the most dissimilar characters, between a philosopher and a common street porter,” Smith wrote in The Wealth of Nations, “seems to arise not so much from nature, as from habit, custom, and education.” One problem is how, in a free and civilized society, some accommodation can be reached with violence-prone people. One way is to punish them when they are found guilty of unjustified violence. Another one is to bribe them with consumption opportunities if they stay peaceful.

Whether Mr. Swift was attracted to the special forces because he already had a comparative advantage in violence or whether he mainly acquired it there, I do not know. Regarding the other army veteran already quoted on the fun of war, the Wall Street Journal also reports:

Civilian life, he added, didn’t offer the same camaraderie or sense of purpose: “War is easy in many ways. Your mission is crystal clear. You’re here to take the enemy out.”

But what did people like him and Mr. Swift learn in school? Didn’t they learn in some way that life is more complicated than camaraderie in ordered missions? Looking at the memoirs Swift self-published under a pseudonym after his desertion (and available on Amazon), it’s not clear that he learned anything other than sports and wrestling in high-school—although his book is engaging. The dysfunctional families in which he and many of his childhood friends lived certainly did not help. He wants to have us believe that his wife did not either, but it’s easy to understand that long deployments are difficult for everybody in the family.

After Swift came back from his last deployment, he faced what psychologists call “adjustment disorder.” He was arrested for domestic violence and charged with false imprisonment, children endangerment, and domestic battery. His wife obtained a protective order and was awarded a large part of his salary. He could not see his four children, which he seemed to love, although perhaps gauchely. In his book, he denies the charges of violence. A felony conviction would have ended his military career, which is the only thing he knew. He deserted before his trial.

Another reflection is in order, which is often neglected in pacifist circles. Men who have some comparative advantage in violence are useful to protect others against unjust violence. Unjust violence will always exist. Protecting even imperfect liberty has a value. And, of course, soldiers are not all, and should not be, violent brutes (“killing machines,” as Trump proudly said of “our boys” from the depth of his wisdom). But even when a (defensive) war and its methods are just, it remains a difficult challenge in a free (or more or less free) society.