I’ll try that argument again by expanding on another view: leaders start wars but the citizens suffer – how is this just?

Are the citizens of a state so responsible for not preventing the internationally unacceptable actions of the leaders of that state, or so responsible for the previous actions or perceived misdeeds of their predecessors, or guilty of a crime by nature of having different cultural values of those of another state, that it is reasonable for the sovereignty of that state to be disregarded such that they can be killed by the orders of the leader of another state?

That is, the rules of just war determine whether it is considered acceptable by political leaders for state A to attack state B.  They do not consider whether the citizens of state B or even state A consider the war to be just.

Is it appropriate in global, internet-connected societies with so much freedom of movement with so much cultural intermingling that it should be considered right and proper that people be killed according to the arbitrariness of their current place of residence at the time of a declaration of war?

In a democracy, is it just that those who vote against a policy should be equally vulnerable to death by the weapons of another state as those who voted the other way?

Where feudalism has been abolished and blind nationalism is no longer credible, I don’t see how ‘a just war’ is possible any more.