This makes it so chess has a one-shot sub game perfect equilibrium: https://en.m.wikipedia.org/wiki/Subgame_perfect_equilibrium. But, the dimensionality of the possible end states is very high, because there are many different configurations leading to a checkmate, so you can’t easily perform backward induction. But you can perform minimax (which is how Stockfish works): https://en.m.wikipedia.org/wiki/Minimax
From a game theory perspective chess is really not at all like an actual war, because the properties of the game are different in almost every conceivable way - not just because of perfect information. But, you can model more complex “games” like war in a way that makes them more similar to chess if you wish. Just be careful because ignoring very fundamental differences like the payoff model could greatly affect decision making - for war, you’d probably rather surrender or make minor concessions in most cases than win at the cost of 99% of your people and infrastructure getting destroyed.