Stanley Kubrick's letters:

And sometimes a script just doesn't have the moral weight required by SK, who turned down Herbert Biberman's The Slaves

July 20, 1964
To Herbert Biberman (one of the Hollywood Ten, blacklisted in 1947 as Communist sympathisers)

I believe it is a powerful story of dubious social value today. If one believed that arousing bitterness was a good thing I would choose from more recent events which seem more relevant. In fact I am convinced that the newspapers, radio and tv today reporting the news are doing as good a job as can be done in acquainting the American public with the ugliness of history. I do not think this ugliness has to be reinforced in art.

Wow. I wonder what Kubrick would have thought of current American media today, whether he would think they are similarly acquainting the American public with the ugliness of history.

I doubt it.