[nanis]

Exactly. In particular, "perfect information" means you know all the strategies available to your opponent. You also know that your opponent knows this. And you know that your opponent knows that you know that your opponent knows that you know all the strategies to your opponent ad infinitum symmetrically.

In this context, a strategy is a function that maps every history of moves by you and your opponent to an action. So, while chess is theoretically a game of perfect information, in practice it is less so.

Real war is not a game of perfect information, because you do not know all the strategies available to your opponent. In addition, you and your opponent's priors may have an intersection of zero measure which makes things very interesting.

War is what happens when a certain kind of people try to play the game of chicken which is usually not taught in the kind of fun programs like master's of international studies for members of the preferred party because it is too sophisticated due to the fact that it admits an infinite number of Nash equilibria ... instead, such programs prefer to focus on prisoners' dilemma which, having a dominant strategy equilibrium, is more suitable to ensure such students can go back to the bureaucracy after having passed their classes with perfect As and get us in to war.