Talks between the U.N.’s nuclear watchdog and Iranian officials – aimed broadly at increasing the transparency of Iran’s atomic program, and specifically at securing access for investigators to Iran’s military facility at Parchin – have again ended without a deal being reached. Iran is widely suspected of having conducted work related to the detonation of nuclear warheads at the facility. Meanwhile, new revelations have been published that last year Iran sought to circumvent a U.N. ban and purchase 100,000 specialized magnets from China for use in its centrifuges. The technology would have enabled Iran to increase the pace of its uranium enrichment by as much as five times. The speed with which Tehran can enrich nuclear material is a critical unknown in debates over whether ongoing negotiations between Iran and the P5+1 countries is a tenable strategy to prevent the Islamic republic from acquiring nuclear weapons. Western diplomats acknowledge that Iran is dragging out negotiations but insist that Western intelligence agencies would still be able to detect – and Western forces would still be able to intervene – if Iran made a decision to acquire nuclear weaponry. Accelerated Iranian enrichment capabilities have the potential to badly undermine that logic.