Why do you think it's more moral/ethical to abstain of supporting military?
What should you do if you support the ethics of self-defense aspects, but do not believe that [your countries] military is acting ethically? What is your morally consistent path? Other than voting, which is part of it.This is a very old form of the argument you are putting forward, and while I can see how people will take it to inform their morals, it's also easy to see reasonable versions that reject it.