Asgari's background suggests that he would have deep knowledge of Iran's national security infrastructure, conventional weapons arsenal and ties to Hezbollah in south Lebanon.

"He held a very, very senior position for many long years in Lebanon. He was in effect commander of the Revolutionary Guards" there.

Ram Igra, a former Mossad officer, said Asgari spent much of the 1980s and 1990s overseeing Iran's efforts to support, finance, arm and train Hezbollah. The State Department lists the Shiite Lebanese group as a terrorist organization.

"He lived in Lebanon and, in effect, was the man who built, promoted and founded Hezbollah in those years," Igra told Israeli state radio. "If he has something to give the West, it is in this context of terrorism and Hezbollah's network in Lebanon."

In a January briefing to Congress, then-Director of National Intelligence John D. Negroponte described Hezbollah as a growing threat to U.S. interests. "As a result of last summer's hostilities, Hezbollah's self-confidence and hostility toward the United States as a supporter of Israel could cause the group to increase its contingency planning against United States interests," Negroponte said.