The problem of war for rational choice theorists is that war is negative sum and agents are risk neutral or averse. Under these assumptions war should always end before it begins with a bargain in which each side walks away with at least its expectation of reward (i.e. rewards from winning * probability of winning); in addition the destruction of war will not occur, so the surplus from that absence of destruction should pacify risk neutral parties as well.
The problem is not a problem if we observe that agents are risk preferring in some situations. I believe there is a city in Nevada
built on that premise.