From Ammoland:

The FBI defines RMVEs as “those that advocate for the superiority of the White race.” The document claims that Islamic “Foreign Terrorist Organizations” (FTOs) are likely discouraged from working with RMVEs due to distrust, but the FBI claims that some RMVEs are sympathetic to Islamists and want to pursue alliances with these groups. It seems like the FBI thinks these groups believe in the “enemy of my enemy is my friend” strategy. The FBI states that both RMVEs and FTOs are brought together by their anti-Semitism and their opposition to liberal Western democracy.

The FBI claims that RMVEs have sought an alliance with Islamic extremists to speed up the collapse of Western society through violence.