Comment by gershy

I misunderstood your point earlier. Not that international law is necessarily always a valid philosophy we should accept, but international law does only consider people to be combatants if they're actively serving. Regardless of what international law says, I would argue that ethically, retired/non-serving army members should not be considered combatants or fair wartime targets (I think I mostly feel this way on the basis that targeting them causes civilian strife - e.g. the company they work for, family/community they support etc. is harmed - with zero war value). And I would say reservists are a more complicated case.