BLACK NATIONALISM, “THIRD POSITION” FASCISM, AND ANTISEMITISM: Chip Berlet discusses the connections. (And follow this link for more specifically on the Nation of Islam.) Berlet’s got a strong ideological position (he’s quite left, leaning toward Marxist, I believe) but his research is generally well-regarded.
One of the things that this illustrates is that too-quick distinctions between “domestic” and “Islamic” terrorism are probably, well, too quick.