...Initially the group was described as "a mysterious group about which virtually nothing was known,"[2] one whose "only members" seemed to be the "anonymous callers" taking credit for the bombings, or one that simply didn't exist. After the MNF bombing, the New York Times reported that "Lebanese police sources, Western intelligence sources, Israeli Government sources and leading Shi'ite Moslem religious leaders in Beirut are all convinced that there is no such thing as Islamic Jihad," as an organization, no membership, no writings, etc.[3] ....
Wright has compared Islamic Jihad to the Black September wing of the Palestinian Fatah,[6] serving the function of providing its controlling organization, in this case Hezbollah, with some distance and plausible deniability from acts that might provoke retaliation or other problems.
...
Adam Shatz of The Nation magazine has described Islamic Jihad as "a precursor to Hezbollah, which did not yet officially exist" at the time of the bombings Islamic Jihad took credit for.[8] Jeffrey Goldberg says
Using various names, including the Islamic Jihad Organization and the Organization of the Oppressed on Earth, Hezbollah remained underground until 1985, when it published a manifesto condemning the West, and proclaiming, “.... Allah is behind us supporting and protecting us while instilling fear in the hearts of our enemies.”[9]
A 2003 decision by an American court named Islamic Jihad as the name used by Hezbollah for its attacks in Lebanon, and parts of the Middle East, and Europe.[10] Just as Hezbollah used another name Islamic Resistance, or al-Muqawama al-Islamiyya, for its attacks against Israel.
By the mid-1980s Hizbollah leaders are reported to have admitted their involvement in the attacks and the nominal nature of "Islamic Jihad" - that it was merely a "telephone organisation,"[12][13] and[14] whose name was "used by those involved to disguise their true identity."...