Rumors of war (think Ukraine) in a complicated world suggest that we look at a simple model of war and peace. Consider a world with two countries, Borduria and Syldavia. State propagandists as well as diplomats often say things like “Borduria has asked Syldavia to respond in writing to its demands.” In reality, it is the government of Borduria that asked something to the government of Syldavia. The government of each country is made of an assemblage of politicians, bureaucrats, and institutions; the latter may include voters or not, or include them to a variable extent.

Economist Jack Hirshleifer’s article “The Dark Side of the Force” reviewed individual incentives in the use of violence in general. Here we are just doing the same for the individual as a participant in a collective decision about the use of violence. In each of our two countries, the incentives of the individuals manning the government and its institutions depend on each one’s self-interest and, crucially, on one’s influence in the process governmental decision-making. The “head of state” or prime minister has much influence and therefore strong incentives to push for war or peace depending on whether one or the other is in his own best interest. The individual voter’s influence is infinitesimal and generates little incentive for him to use resources to defend his self-interest through smart voting or just voting. Let’s define “the ruler” as the group of individuals who have decisive influence on the government’s decision. (The King of Prussia and his generals appear on the featured image of this post.)

Borduria and Syldavia can be very different countries if power is distributed differently within them and if the incentives of individuals manning governing institutions consequently differ. In a country where widespread voters’ dissatisfaction—dissatisfaction strong enough to bring voters to follow the crowd at voting polls—has a chance to throw the rascals out, the ruler has comparatively more incentives to avoid war. Hence, the frequent observation that democratic governments go to war less often. Similarly and probably more importantly, the more a government is constrained on the use of its “human resources” (subjects or citizens), the lower the incentives of the ruler to wage war, ceteris paribus. Let’s assume that in both Borduria and Syldavia, the only constraint on government action is its need for popular support, either through formal elections or less formal means.

At least in contemporary times, where a large number of people (it is hoped) understand that blowing up capital (factories, bridges, etc.) is not the road to prosperity, the ruler of Borduria, who wants to keep or increase his power, will normally want peace in order that his subjects be prosperous and happy, that is, content and quiet. It is the same in Syldavia.

If his subjects are restless and currently threaten his power, the ruler of Borduria will have more incentives for war, ceteris paribus. War will distract and occupy the subjects and allow the ruler to increase his control over them, not counting his possible glory if he wins the war. War will also generate more identification of his subjects to “Borduria” and its flag: it’s “us Bordurians against them Syldavians.” Whether the incentives of the Bordurian ruler will go more toward war or peace will depend on where his personal expected net gain is the largest, or where the minimization of his expected net cost is the smallest. Again, the same incentives play in Syldavia.

In this simple model, war happens when the ruler (as defined) calculates that it is in his best (probabilistic) interest given his social, political, and economic constraints. He may be pushed into war by mobbish nationalism but, most of the time, he or his predecessor is the one who has inflamed it.

Assume that the government of Borduria declares war. What will be the position of a Bordurian classical liberal or libertarian in Borduria is quite obvious: he will oppose a war that responds to the ruler’s self-interest. It is not as obvious what will or should be the position of a Syldavian classical liberal or libertarian.

There are many ways to bring this simple model closer to reality. Other countries than Borduria and Syldavia exist in the world, including “allied countries.” If the Bordurian government starts military operations, the Syldavian government may, as a substitute for war, impose economic sanctions on its own subjects in their dealings with Bordurian entities. Or perhaps the Bordurian or the Syldavian ruler is a Madisonian angel, morally detached from his personal self-interest?

Another complication is whether we may consider a “country” as a protection club against foreign tyrants, as James Buchanan’s constitutional political economy and other classical-liberal theories would suggest (in certain circumstances). But which country today fits this model except (perhaps) for the strange case of Switzerland?