Testifying at a US Senate hearing, Hayden said that "to strengthen the common ground that all Iraqis can share, the government of Prime Minister (Nuri al-) Maliki will have to overcome several formidable obstacles."
"Internal divisions and power struggles among the Shia make it difficult for Shia leaders to take the actions that might ease Sunni fears of domination," he said at the US Senate Committee on Armed Forces.
"Radical Shia militias and splinter groups stoke the violence, while brutal Sunni attacks make even moderate Shia question whether it is possible to reconcile the Sunnis to the new Shia-dominated power structures," the Central Intelligence Agency chief said.
In addition, neighbouring Iran "is stoking violence and supporting even competing Shia factions," he said.
"The Sunnis are even more divided," he added.
And even if the Iraqi government were better supported by the various
communities, the difficulties remained titanic, he said.
"Iraq's endemic violence is eating away at the state's ability to govern," he said.
"The security forces are plagued by sectarianism and severe maintenance and logistics problems; inadequate ministerial capacity is limiting progress on key issues; and the civilian bureaucracy, buffeted by corruption, inefficiency and partisan control, is not currently up to the challenge of providing better services to the Iraqi people."
Complicating the situation, the CIA head said, was al Qaeda's presence in Iraq which "continues to foment sectarian violence and seeks to expel coalition forces."
He warned that an al Qaeda victory in Iraq "would mean a fundamentalist state that shelters jihadists and serves as a launching pad for terrorist operations throughout the region -- and in the United States."

Copyright AFP (Agence France-Presse), 2006