LONDON (Reuters) - Abu Musab al-Zarqawi's al Qaeda in Iraq is among four main groups leading an insurgency against U.S.-led and Iraqi forces that owes its resilience partly to canny exploitation of the Internet, a report said on Wednesday.
The International Crisis Group, a non-profit organization that monitors conflicts, analyzed insurgent publications and Internet postings to argue that the rebel groups had steadily developed sophisticated communications and coherent leadership.
Zarqawi's militant group, viewed by the United States as its deadliest foe in Iraq but whose importance others dispute, "appears to be surprisingly well-structured", the ICG report said, citing a study of its communiques.
"It should neither be blown up into a Leviathan nor ignored as a mirage, but rather considered as one among a handful of particularly powerful groups," the report concluded.
The report named Ansar al-Sunna, the Islamic Army in Iraq and the Islamic Front of the Iraqi Resistance as the other main groups broadly sharing a Sunni Islamist and nationalist agenda.
These large armed groups or networks are "well organized, produce regular publications, react rapidly to political developments and appear surprisingly centralized", it said.
They were less divided between Iraqi nationalists and foreign fighters than often assumed and remained relentlessly hostile to the United States and its Iraqi "collaborators", despite efforts to draw them into the political process.
Increasingly confident of victory, the rebels have shown themselves sensitive to Sunni Arab opinion and willing to alter their tactics -- such as beheading hostages and attacking voters -- to avoid alienating support, the report said.
U.S. counter-insurgency tactics aimed at killing enemy fighters, eliminating their leaders and driving them from their strongholds do not appear to be working, it argued.
Insurgent groups, including Zarqawi's, had replenished their ranks and their leaders, while exploiting Sunni Arab hostility to the U.S.-led occupation and to the Shi'ite Islamist parties that now dominate Iraq's elected government.
The report said the insurgents were arguably more susceptible to political than military pressure, citing last year's elections, televised confessions of captured fighters and accusations of sectarianism and brutality.
Any successful counter-insurgency effort would seek to erode the perceived legitimacy of the rebels and would require U.S. and Iraqi forces to avoid prisoner abuse and the use of sectarian militias against their Sunni Arab opponents, it said.
