During the show, I was a participant in the YouTube chatroom and mentioned that Stalin had defined fascism as the enforcement of capitalist social relations through violence. A member of the staff administrating the chatroom asked for a reference to that, and I was not able to dig it up before the end of the show. However in the interim, I managed to find it.
It's from an interview between J. V. Stalin and H. G. Wells on 23 July 1934. The context is the building up to the second world war, where capitalism is decaying into fascism throughout Europe and Stalin notes how fascism is arising out of a desperate desire on the part of the capitalist class to preserve the old system (old system being capitalism -- in contrast to the new system of socialism as advanced by the communists).
The interview in its entirety can be found here:
A little over half-way down the page is the relevant quote: "Yes, you are right when you say that the old social system is breaking down; but it is not breaking down of its own accord. Take Fascism for example. Fascism is a reactionary force which is trying to preserve the old system by means of violence." -- J. V. Stalin.
I apologise if this is not the right spot for this but I cannot figure out where/how to contact the relevant staff.