Chris McGreal in Washington guardian.co.uk, Friday 17 February 2012 17.27 GMT http://www.guardian.co.uk/world/2012/feb/17/us-officials-iran-sanctions-military-action Officials in key parts of the Obama administration are increasingly convinced that sanctions will not deter Tehran from pursuing its nuclear programme, and believe that the US will be left with no option but to launch an attack on Iran or watch Israel do so. The president has made clear in public, and in private to Israel, that he is determined to give sufficient time for recent measures, such as the financial blockade and the looming European oil embargo, to bite deeper into Iran's already battered economy before retreating from its principal strategy to pressure Tehran. But there is a strong current of opinion within the administration â including in the Pentagon and the state department â that believes sanctions are doomed to fail. But long-held doubts among US officials about whether the Iranians can be enticed or cajoled into serious negotiations have been reinforced by recent events. "We don't see a way forward," said one official. "The record shows that there is nothing to work with."