In the end good/evil are myths. They are human constructs and they can change depending on time and place. Ethics is not a hard science and your belief that something is good does not make it a fact.
The military can cause a lot of destruction and grief around the world, no doubt, but it can also cause a lot of good and stability. In the real world there will always be "winners" and "losers" An action that benefits you may directly or indirectly hinder someone else.
Our military's mission is to defend our country and that means that sometimes other countries will lose if they decide to engage. Inevitably there will be innocent casualties. This will never ever change. It is an honorable thing to do what we can to minimize it but unrealistic to expect it to ever go away.
You will likely see the world in a different light the older and more experienced you get. You're not a good person. You're not a bad person.
You're just a person.
Also, ethical myths have very real effects on societies, but they are myths nonetheless. That realization may be inconvenient to some and that's fine.
Also, if that bad accounting is leading to the death and torture of humans.
I am of the opinion that a "well it's far removed from me even though that is what the organisation's main goal is" stance is doing yourself a disservice.
Not murder. Unfortunately, people are killed in war. Not the same thing.
I don’t think the US has a good reputation as peace makers, albeit the opposite.
Depends on which part of the world are you asking.
I live in Eastern Europe. US military (and NATO, but I am just repeating myself) is currently the only reason why Russian armies are not marching through our streets. Western Europe alone would gladly sacrifice us at any moment.
I understand that if you asked e.g. someone from South America, you could get a dramatically different answer. But I am speaking for myself right now.