I’ve previously faced a similar decision. Here is why I decided to steer clear of the American war machine:
Other commenters have pointed out that American military supremacy is preferable to military supremacy by a different power. I agree. However, most of what the US military is actually doing has nothing to do with great power conflicts. The military has mostly been involved in fighting wars in third world countries. The chance that you help maintain US military supremacy is low, the chance that you create something that will help soldiers kill someone that EA is trying to help (via GiveDirectly, Givewell, etc.) is high.
I believe it would be challenging for a moral person to exist in the social context of a group that is working on behalf of the U.S. military. I have a friend who I believe to be a good person at heart. He has always cared for the people around him. When offered enough money, he took a job working on a nuclear weapons related technology. At first, he justified this to himself by saying that the he was making the missiles more accurate so they could kill fewer people. But when he got to his job, that’s not how his coworkers viewed things. They believed that what they were doing was morally okay because they didn’t extend their moral circle past the borders of America. It’s very difficult to convince yourself that you’re a good person when your coworkers are flippantly discussing how they are working to help the military kill people. My friend drinks a lot now.
The military industry isn’t the only place offering good pay. The trade off isn’t between not doubling your pay vs. working for the military industry. It’s between putting more time/energy into a job search vs. working for the military industry. You can likely find a job with comparable pay elsewhere if you keep looking.
That makes sense. As to my first point, it’d point you towards this Wikipedia page. All but one war that the US has fought since WW2 has been waged against a third world country.
The US has killed over 400,000 civilians since 2001 via our wars in the Middle East.