How do you reckon it would work when it comes to age? Is the vote limited just to people of military age? Does this mean that whether or not to declare war effectively falls in the hands of ~18 - 30 year olds?

Or is it open to everyone and even some old warhawk could be drafted? Are handicapped people not allowed to vote? Women that don't meet combat standards?

There is always the option to draft them into some sort of non-combat role. But if you knew you were only going for a non-combat role, it could be a lot easier to vote "yes".