Hopes for a quick diplomatic breakthrough in the long-running stalemate over Iran’s nuclear weapons program have been dimmed by Iranian backtracking on a tentative agreement reached on October 1 in Geneva and Iran’s foot-dragging on future negotiations. Reuters today quoted an anonymous senior Iranian official as saying “Time is on our side” and declaring that Iran plans to slow-walk the diplomatic negotiations that will resume on October 19 by sending junior officials who do not have the authority to make firm commitments.

This confirms previous suspicions that Tehran will exploit the P5+1 talks to engage in a diplomatic filibuster that will defuse momentum for further international sanctions while Iran continues to move forward on its nuclear program.

The value of the “agreement in principle” reached in Geneva on October 1 also has been substantially downgraded by a blockbuster revelation publicized today in a Washington Post column by David Ignatius. Ignatius cited an article in Nucleonics Week that reported that Iran’s supplies of low-enriched uranium appear to be contaminated by impurities that could wreck centrifuges if Tehran tries to boost it to weapons grade fissile material. Ignatius wrote:

You’ve got to hand it to the Iranians, though, for making the best of what might be a bad situation: In the proposal embraced in Geneva, they have gotten the West to agree to decontaminate fuel that would otherwise be useful only for the low-enriched civilian nuclear power they have always claimed is their only goal.

Meanwhile, the Wall Street Journal today reported that U.S. intelligence officials are considering whether to rewrite the controversial 2007 National Intelligence Estimate on Iran’s nuclear activities. The findings of that NIE, which concluded that Iran had suspended its nuclear weapons program in 2003, have been disputed by intelligence agencies from Britain, France, Germany and Israel. Even IAEA officials, who have long treated Iran with kid gloves and accorded it the benefit of the doubt, have been critical of the NIE’s findings. The recent revelation of Iran’s secret uranium enrichment facility hidden inside a mountain near Qom also has cast further doubt on the NIE.

Congressional pressure is building to review the flawed 2007 NIE. Last week Rep. Pete Hoekstra, the ranking Republican on the House Intelligence Committee, urged Congress to establish an independent “red team” of outside experts to review the 2007 NIE in light of disturbing recent revelations about the Iranian nuclear program. Rep. Hoekstra is right: a re-evaluation of the NIE is long overdue.