BBC Online :Islamic State militants are the most dangerous threat the US has faced in recent years, Washington has warned.Defence Secretary Chuck Hagel said US air strikes had helped to break the Islamist advance in Iraq, but the militants could be expected to regroup.America’s top general Martin Dempsey stressed that IS could not be defeated without attacking their base in Syria.The warnings come after IS posted a video showing the beheading of US journalist James Foley.The US has now begun a formal criminal investigation into Foley’s death, with US Attorney General Eric Holder warning that the country has a “long memory”. It has emerged that a special US military mission tried but failed earlier this summer to rescue Foley and other US hostages held in Syria.The militants had also reportedly wanted a $132m (£80m) ransom for his release.Speaking at a news conference on Thursday, Hagel described IS as an imminent threat.”They are beyond just a terrorist group. They marry ideology, a sophistication of strategic and tactical military prowess, they are tremendously well-funded… this is beyond anything that we have seen.”Meanwhile, Gen Dempsey, the chairman of the US Joint Chiefs of Staff, said IS was “an organisation that has an apocalyptic, end-of-days strategic vision and which will eventually have to be defeated”.”To your question, can they be defeated without addressing that part of their organisation which 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.”Neither Hagel nor Gen Dempsey announced a change in the limited military campaign adopted by Barack Obama, and the US president is unlikely to deepen his involvement in Iraq or Syria, the BBC’s Barbara Plett Usher in Washington reports. But US officials did not rule out additional action against IS in Iraq or Syria, our correspondent adds.
