Today I watched some YouTube videos about the World Wars, and in particular how the first one came about. It did seem like a sequence of plausible sounding steps that led to a giant war. But there is an abstract level at which I still feel confused. Which is one where initially there are basically a very large number of humans who each very much don’t want to die presumably, most of whom have very little reason to kill almost any of the others. Then somehow this all turns into everyone putting huge amounts of effort in and risking their lives to kill each other. It is as if you told me that you had a barn full of soaking wet hay, and it turned into a big bonfire.

I suppose the natural explanation is that there are rulers, or in more game theoretic terms to match the incentive-level of my confusion:

  • Some people start out in pre-arranged relationships of control over others, so that they can insist that those people risk their lives to do things that they don’t otherwise care about, e.g. kill strangers. In particular, the controllers can otherwise punish the soldiers-to-be harshly. They can do this because societies generally have an arrangement where anyone can be punished for failing to follow the rules, including whatever the leader says (e.g. ‘we are going to war now’) and the rules about upholding of punishments. This means individuals can end up doing things that are overall costly for them, because their leader can impose a larger cost if they don’t do it. If people succumb to such threats, the threats don’t need to be carried out often, and so it can be cheap for those in control to ask a large number of controlled people to do things otherwise strongly against their interests. (e.g. a government can extract far more in taxes from a population than the cost of incentivizing them to pay taxes.) So this equilibrium is fairly stable, though we haven’t considered alternate sources of threats (e.g. another party saying they will punish you if you listen to the ruler).
  • Once you have large groups controlled by decisionmakers who don’t suffer the costs of their decisions, it becomes unsurprising if the outcome is massive costs to almost everyone concerned with little gained by anyone.
  • You might only need one such controller of others to prefer war, as long as the others or their citizens consider it worth defending from the attack.

I don’t know how much this explains though. And there are probably other things going on. For instance, here’s Winston Churchill in 1914:

Everything tends towards catastrophe and collapse. I am interested, geared up and happy. It is not horrible to be built like that? The preparations have a hideous fascination for me. I pray to God to forgive me for such fearful moods of levity.

And in 1916:

I think a curse should rest on me – because I love this war. I know it’s smashing and shattering the lives of thousands every moment and yet, I can’t help it, I enjoy every second of it.