I’d prefer requiring they have children that serve in the armed forces. Nothing makes you think twice about sending people to die in foreign lands as much as your own child being right there with them.
Well this already happens at some places, but due to some "internal works" (i.e nepotism) their children are always highly ranked and can sit at the comfort of their home country while a war is waged.
Then you'd just be optimizing even more for sociopathic politicians. It's not like caring more about your children than power is some universal behavior in humans.