Using the scenario of different states and the electorial college, if Utah invaded washington and its neighboring states, for the sole purpose of taking control of the country, and killed off large chunks of the population but failed, should Utah still be able to claim, come census time, we should get more electorial votes, why, we have more people, how? Because we killed off chunks of the other states populations. If one state reduces another states population in a bid for power, do they get a pass? that is what you are advocating.
The whole point is that. Other than prosecuting those directly involved in the crime, technically and practically, nothing can be done.