Pentagon chiefs warn of long, cross-border fight against IS

Pentagon chiefs warned Thursday of a protracted, cross-border war against Islamic State, two days after the group released a video showing the beheading of an American journalist.

When asked on Thursday if the campaign could go beyond Iraq, Army General Martin Dempsey said, “Can they be defeated without addressing that part of the organization that resides in Syria? The answer is no."

“That will have to be addressed on both sides of what is essentially at this point a non-existent border,” said Dempsey, who is chairman of the Joint Chiefs of Staff.

Washington has launched air strikes in past weeks against IS positions in northern Iraq to bolster Kurdish resistance against the fighters. IS warned the U.S. against continued attacks after announcing the execution of journalist James Foley on Tuesday — claiming they would kill more hostages unless the aggression ended.

The murder has stoked fears around the world that the territory IS has seized in Syria and northern Iraq could become a staging ground for a new round of terror attacks.

Some 12,000 foreign fighters from 50 countries, including the U.S., have gone to fight in Syria, the U.S. State Department said Thursday. A U.S. official speaking on condition of anonymity said more than 100 Americans have traveled or tried to travel to Syria to join the fight.

Thousands more are believed to be operating in Iraq.

Defense Secretary Chuck Hagel said Thursday that IS poses an imminent threat “to every interest we have, whether it’s in Iraq or anywhere else.”

“They are beyond just a terrorist group. They marry ideology, a sophistication of … military prowess,” Hagel said. “They are tremendously well-funded. This is beyond anything we’ve seen.”

Dempsey echoed Hagel’s statement, saying, “This is an organization that has an apocalyptic, end-of-days strategic vision and which will eventually have to be defeated.”

Wire services