When you say capitalism has only worked because of the exploitation of minorities, that's a reasonable argument. The labor of the subjugated is a direct input to the capitalist system.

But when you tie that to military strategy and the use of nukes, I don't see how that was inherent to capitalism. We used them first because we made them work first, and it happened while we were engaged in a huge bloody war. I'm not saying that makes it right or wrong, just that the unique circumstances weren't about the economic system.

If anything, given the number of German refugee scientists on the Manhattan project, it would make more sense to attribute development of nukes to fascism.