Brotherhood of Nod has always been in C&C since the first game.

Strangely enough, this reminds me that, at the time, even as a kind, I thought it was kind of unrealistic that there was no way that a stateless belligerent faction could amass military hardware and tech enough to threaten a global superpower across multiple different continents.

Then Al Quuaeda and ISIS came along and did just that.