Created by a split from the Fatah in 1974, the Abu Nidal Organization (officially named Fatah - the Revolutionary Council) is an international organization named for its founder Abu Nidal. The group is also known as the Arab Revolutionary Brigades, Black September and the Revolutionary Organization of Socialist Muslims. It has an estimated members of several hundred.

It has carried out terrorist attacks in 20 countries, killing or injuring almost 900 persons. Targets include the United States, the United Kingdom, France, Israel, moderate Palestinians, the PLO, and various Arab countries. Major attacks included the Rome and Vienna Airport Attacks in December 1985, the Neve Shalom synagogue in Istanbul and the Pan Am Flight 73 hijacking in Karachi in September 1986, and the City of Poros day-excursion ship attack in Greece in July 1988. Suspected of assassinating PLO deputy chief Abu Iyad and PLO security chief Abu Hul in Tunis in January 1991. ANO assassinated a Jordanian diplomat in Lebanon in January 1994 and has been linked to the killing of the PLO representative there. The group has not attacked Western targets since the late 1980s.

The group maintained a presence in Iraq and Lebanon, its operations in Libya and Egypt were stopped by local authorities in 1999. The choking of funding from Middle Eastern governments caused the organization to slip away in obscurity.

The United States has claimed the group has received funding from the governments of Iraq, Libya, and (until 1987) Syria.