Abu Nidal Organization

While now considered inactive, the Abu Nidal Organization (ANO) was an active and feared Middle Eastern terrorist group, primarily involved in an international and transnational approach to the Israel-Palestine Conflict. It is also known as the Fatah Revolutionary Council, the Arab Revolutionary Brigades, or the Revolutionary Organization of Socialist Muslims. [1] While some of its names include "Muslim", it is primarily secular, and a political enemy of the Palestine Liberation Organization as well as the State of Israel. It remains on the US list of terrorist organizations.
Abu Nidal
Abu Nidal was the pseudonym of Sabri al-Banna, a former PLO leader who broke off, in 1974, when the parent organization considered establishing diplomatic relations with Israel. In the fifties, he joined the Arab nationalist Ba'ath Party, and, in 1967, the PLO, representing its Fatah faction in Sudan and Iraq.
After he left the PLO, it sentenced him, in absentia to death for attacks on Palestinians. Jordan did the same in 2001 for the assassination of a Jordanian diplomat, Naeb Imran Maaytah, in 1994. In August 2002, Abu Nidal was reported dead in Iraq.
Operations
In the 1980s, it was among the world's most dangerous groups, and received support, at various times, from Iraq, Syria and Libya. Saddam Hussein, who had assisted it in the beginning, ejected it in a ploy to gain US support in the Iran-Iraq War, but invited it back after that war ended.
Syria expelled it in 1987 and Libya in 1999, under US and international pressure to deny terrorism.
Possible relationship with al-Qaeda
While it has been suggested, by Douglas Feith, that ANO cooperated with al-Qaeda, this seems unlikely. ANO's peak activity was before al-Qaeda really formed, and it was secular rather than Islamist.