He asked Miller to put the play's villains as communists. This inspired Miller to write how the heightened fear of communism was harmful. Furthermore, he felt motivated to write about this subject.
We can arrive at this answer because:
Arthur Miller had written a play called “The Hook,” which talked about union corruption on the edge of Brooklyn.
One day he was visited by the head of Colombia pictures, who asked Miller to make modifications to the play and put the villains to represent the communists.
Miller refused to do that and didn't like the interference, but the situation allowed him to come up with a great idea, and that idea allowed him to write "The Crucible."
Miller knew how the attempt to vilify the communists at all costs was wrong on the part of the Americans, as it generated an exaggerated fear that was very harmful to everyone.
More information about "The Crucible" at the link:
