Communism is still alive. What it takes to defeat a Delusion is to have people forced to look at it. As long as communists can flee to another country, they don't have to face the states they messed up. Same with Islam. Put a Muslim country of a deserted island and it will stop that within a few generations. However, Islam survives as long as they are given someone to blame.
This is the problem of open borders policies. No, I'm not racist against Muslims (Islam is not a race) I realize that Islam would implode if it has nowhere to blame and nowhere to spread to. This happens either by containment or by letting it crowd itself out over the whole Earth. The Revelation is talking about the Red-Green Bloc, and how the Cult of Babylon will spread through the Earth only for the one-government and one-religion to both fall. It will be a nasty mess that will likely kill off most people before such things have nowhere to go.