I feel too old for service now, but out of curiosity - where can people serve if they don't agree with the political/military climate? Ie, I always wanted to se

I feel too old for service now, but out of curiosity - where can people serve if they don't agree with the political/military climate? Ie, I always wanted to serve but I didn't want to go kill largely innocent people in other countries. Eventually I realized that the police force was far more up my alley. Yet, even that is difficult due to the militarization of the police force and the general unrest between civilians and police. Is there an area that feels largely.. good? A mostly positive force for humanity? To serve the betterment of others, not so much war? NOTE: I hope you (readers) can take my question at face value, and not argue my opinions regarding police and/or military. No judgement intended, but my question is all I am hoping to discuss :)