US warns of long cross-border war against IS

WASHINGTON: The United States admitted Thursday that the Islamic State is the most dangerous group it has faced in recent years, and warned that the Middle East faces a long-term battle to defeat it.

Pentagon chiefs said the militant group could be eradicated if local Sunni communities reject it and regional powers unite to fight it, but only if the battle is taken into Syria and not just Iraq.

Speaking after the US military revealed it had already carried out a failed hostage rescue mission inside Syria, and against the backdrop of new air strikes in Iraq, they warned IS poses a considerable threat.

"They marry ideology and a sophistication of strategic and tactical military prowess," Defense Secretary Chuch Hagel said about the "barbaric" militants. "They are tremendously well funded. This is beyond anything we have seen."

General Martin Dempsey, chairman of the Joint Chiefs of Staff, said the group "has an apocalyptic end of days strategic vision that will eventually have to be defeated."

Dempsey warned the militants vision of a wider Muslim caliphate could "fundamentally alter the face of the Middle East and create a security environment that would certainly threaten us in many ways."

"Can they be defeated without addressing that part of the organization that resides in Syria? The answer is no," he said, when asked if the campaign against the group could go beyond Iraq.

He spoke of a "very long contest" that could not be won by US military prowess alone, but only with regional support and that of "the 20 million disenfranchised Sunnis that happen to reside between Damascus and Baghdad."

Washington has launched air strikes against IS positions and boosted arms supplies to Kurdish forces, but still wants Baghdad´s Shiite-led government to open its arms to Sunni moderates.

The warning came after IS released a video this week showing a militant with a British accent beheading American journalist James Foley, and threatening a second US hostage.

The murder has stoked fears in Britain and beyond that the territory the militants have seized in Syria and northern Iraq could become a launching pad for a new round of global terror attacks.

And as part of that worrying trend, the US State Department estimated that there are about 12,000 foreign fighters from at least 50 countries in Syria.

A US official estimated that of those, more than 100 US citizens have tried to travel or actually traveled to Syria to join radical groups like the IS.