For the people at the top this is certainly clear. For the untold hundreds in the middle and bottom I think it is far less clear.

Einstein famously refused the first presidency of Israel because he could see that Israel as an ethno-religious state could only lead to apartheid. But Einstein was already famous and nearing the end of his career and life at that point.

If you're a low/mid-level physicist and asked to work on a top secret project that you might not even know what it is before you have to yes, you have a huge dilemma. End your career for something you may not even believe can be done? Refusing such a job during WWII would be career ending, and it is not like there are massive job prospects for research physicists.

When I was graduating college in the late 80s as an electrical engineer, research into rail guns (aka Gauss gun, coil gun) was in its infancy. Super cool technology and very complex math. I had an opportunity (and an inside contact) at a young company in a great location to go into that business. I turned it down because a) I didn't want to go the "research engineer" route because future job prospects are few and political. How was I to know how the weapons industry in the US would explode (pun intended) in the coming decades?; and b) I didn't want to work on weapons because of the product.

The difference between me and most of those people working on the bomb is huge. No pressure on me. No career risk for me. No issue of patriotism. I think that context matters.