What is the largest terrorist group in Iraq?

Answer 1

Currently, as of 2015, Islamic State is the most powerful terrorist group in Iraq with at least 20,000 members, but it was not always this way. Before Islamic State's surprising victories in 2014, this question would be much harder to answer with "largest" and "terrorist" being nebulous words.

If the word "largest" is meant to mean most ubiquitous, then the answer is certainly Al Qaeda since the American Invasion. Al Qaeda operates like a McDonald's, Franchising cells across any country in which it exists. In addition, smaller jihadist organizations will reach out to Al Qaeda for funding and the name recognition. In return, Al Qaeda will claim that this smaller independent jihadist organization is part of its ranks, even though their objectives may be different than those of the Al Qaeda leadership.

If the word "largest" is meant to mean the largest internal membership, then the answer is a lot murkier. There are numerous violent groups that operate within the Sunni Triangle (Baghdad-Falluja-Tikrit) and numerous Shia organizations which operate throughout lower Mesopotamia. Accurate accounts of organizational membership almost never exist because the cell structure is loose. In addition, most individuals so affiliated only know the names of those fellow group members that they are very close to so as to limit the efficacy of post-capture interrogation.

If the word "terrorist" only refers to the international organizations certified terrorist organizations by the United States and/or Europe, many of the violent groups in Iraq are necessarily excised because these violent groups are regional and would better be classified as "gangs with machine-guns". Violent groups, such as the one that controls Sadr City (a district of Baghdad), are responsible for many more deaths in Iraq than the certified terrorist organizations. What is also important to note is that many of these violent groups target Iraqis who are either neutral to United States interests or opposed to United States interests as these groups are jostling for power in the new Iraqi structure. The "terrorists" are far from a monolith.