WASHINGTON - Federal authorities today revealed a major international undercover sting in which Philadelphia-based federal agents arrested an Iranian arms dealer in Eastern Europe and secretly extradited him to the United States. The Iranian, who has been quietly jailed in a Philadelphia-area prison for nearly two years, pleaded guilty to charges in 2008, officials disclosed today. The case had been sealed from public view while U.S. Immigration and Customs Enforcement (ICE) agents scoured the dealer's laptop to pursue hundreds of leads about Iran's covert effort to acquire American military gear, law-enforcement sources said. "This guy was very prolific - there...