Hugh Pickens writes writes: "AFP reports that Iranian nuclear scientist Mostafa Ahmadi Roshan was killed instantly in a Tehran car bomb assassination which occurred in front of a university campus in east Tehran that Iran has blamed on Israel that threatens to ignite a dangerously tense international standoff over Iran's atomic program. Roshan had specialized in making polymeric membranes to separate gas and was involved in purchasing equipment for the Islamic republic’s main nuclear enrichment facility. Iran uses a gas separation method to enrich its uranium. "The method of this terrorist action is similar to previous actions that targeted Iran's nuclear scientists," says Safar Ali Bratloo, deputy governor of Tehran province. Three other Iranian scientists were killed in 2010 and 2011 when their cars blew up in similar circumstances. Tehran has blamed the assassinations on Israel and the United States while both countries have denied the accusations. The killing sharpened an international confrontation over Iran's nuclear program in which threats and counter-threats are being increasingly backed with militarized displays of muscle as western nations, the United States in the fore, are steadily ratcheting up sanctions on Iran with the aim of fracturing its oil-dependent economy. Tehran's determination to forge ahead with its nuclear activities have been underlined by the International Atomic Energy Agency's confirmation that Iran had begun enriching uranium at a second facility — its Fordo fortified underground bunker."