What are the halachot for conscription in say USA. If a religious Jew is conscripted, to fight to defend Israel, for example, should he consider himself part of the milchement mitzva? Should he keep all the laws of war to the best of his ability, e.g. forgo kosher food, forget about his family, and allow non-combatants to flee?
What if the country he is fighting for has its own interests which might put it in a position against Israel in some way?
Perhaps in that case (or any case) he's not allowed to join, and must face the consequence, such as prison or execution?
Sorry for the grim subject. Where is this discussed?