Earlier quoted context omitted.
> It’s a bit like blaming the scientists of the Manhattan Project for dropping the atomic bomb. Consider Joseph Rotblat. He worked on the Manhattan Project because believed that it was needed as a deterrent against a German nuclear weapon. After he learned that Germany had given up on the bomb, he left the Manhattan Project - the only one to do so - and felt betrayed by its use in Japan. "Rotblat believed that scient…
There's some evidence that the use in Japan was partly an attempt to deter the Soviet Union from future aggression.
If the Manhattan Project is a useful comparison, then we have to take the totality of the people working on project, including the one person who quit, for moral reasons.
He 'believed that scientists should always be concerned with the ethical consequences of their work'.
In other words, yes, we should apportion some blame to 'the scientists of the Manhattan Project for dropping the atomic bomb'.
(For that matter, Philip Morrison was one of those scientists. He helped load the atomic bombs onto the planes that made the two bomb runs. Certainly there's direct blame there, if blame is to be placed.)
Certainly the rest of the scientific staff did not have the same views, or at least, didn't place the same weight on the different aspects of the ethics.
Even then, remember that Oppenheimer remarked that he felt he had "blood on my hands" because he and others of the scientific staff thought the bombing of Nagasaki was unnecessary. Truman later told Acheson "I don't want to see that son-of-a-bitch in this office ever again."
Regarding your point, and quoting from the WP page on Rotblat: "Rotblat continued to have strong reservations about the use of science to develop such a devastating weapon. In 1985, he related that at a private dinner at the Chadwicks' house at Los Alamos in March 1944, he was shocked to hear the director of the Manhattan Project, Major General Leslie R. Groves, Jr., say words to the effect that the real purpose in making the bomb was to subdue the Soviets."
I interpret that to mean that Rotblat would have considered using the bomb against the Soviets in the way you summarized it as being sufficiently unethical that he would not work on it.