The documentary Hypernormalisation talks about the strategies Bezmenov lines out the four basic stages from a slightly different angle. Worth a watch. Things have gotten even more frightening since this warning. Bezmenov talks as if it's only the left that's targeted by ideological subversion, and maybe that was the primary strategy at the time, but it sure seems like both sides are are in play now.

https://www.filmsforaction.org/watch/hypernormalisation-2016...