No need to look further than the fall of the Soviet union for your answer. They themselves are the blueprint for their demise. They no longer have any country to which to defect. This game of thrones is no longer limited, through insane hubris, to a single host, one country to be exiled from, this phase is global.
I'm not sure why you assume they are competent. They have simply used subterfuge and the shadows as their shield to go about their evil work and use sin compounded upon sin. Weakness isn't a substitute for merit.
If Western civilization doesn't regain it's feet, I'm quite sure the Chinese with euthanize any remaining outbreak, once the cancer has killed its perceived enemies, falling not prey to notions of a common theology or mandatory empathy for 20c war narratives.
Perhaps there will be many more hundreds of years of dark ages soon, but like the shots, it wasn't of our choosing.
