Bombing Kills Top Figure in Hezbollah

In Tehran, Iranian Foreign Ministry spokesman Mohammad Ali Hosseini called Mughniyah's killing "a blatant example of Israeli state terrorism," according to Iran's state news agency. Hosseini said Mughniyah's death would open "a new page in the brilliant history of people's struggles with the Zionist regime."

Hezbollah made no explicit threat to retaliate, but Israel braced for a response.

"No matter who did it, they're going to blame us," said Yossi Alpher, a former senior official in Mossad. "There almost certainly will be an attempt at revenge."

Mughniyah's life mirrored the ebb and flow of Lebanon's conflicts, as well as the evolution of Hezbollah, which has risen from its beginning as a clandestine group after Israel's 1982 invasion of Lebanon to become one of the key political actors in the country today. Throughout, its military wing has borne the imprint of Mughniyah, described by Lebanese officials as more action-oriented than devout.

Among his Iranian allies, Mughniyah was reportedly called "the fox." In Lebanon, he was widely known among his supporters as Hajj Radwan, his nom de guerre.

He first came to light after 1982, when Lebanon was still mired in civil war. He was reputed to be the commander of Islamic Jihad, a pro-Iranian group that coalesced into Hezbollah, which officially emerged years later. He was blamed in the kidnappings of many of the more than 50 Americans, Frenchmen, Britons, Germans and other foreigners who were abducted during the civil war's grimmest days.

His name emerged again in 2006, when he was said to have played a role in organizing Hezbollah's defenses in Lebanon during the 33-day war with Israel.

"This is a loss of a major pillar in resistance work. He was an expert at making victories and building fighting capacities against Israel," said Ali Hassan Khalil, a member of parliament with Amal, a Shiite group allied with Hezbollah. "He played an essential role in all resistance activities, especially the last war."

Mughniyah's whereabouts were always a matter of speculation. People said he was in the southern village of Tir Dibba, where he was born to peasant parents, or somewhere in Iran, whose government had reputedly issued him a diplomatic passport. Few pictures of him existed, and he was said to have undergone plastic surgery more than once to conceal his identity.

Over the years, both Israeli and U.S. agencies had pursued Mughniyah, but until Tuesday he had frustrated his enemies' best efforts.

"The fact that he was able to stay alive all this time is a credit to his capabilities," said Yoram Schweitzer, a retired Israeli intelligence official.

Yatom, the former Mossad chief, said Mughniyah trusted almost no one and never made himself visible -- traits that made him exceptionally difficult to track.

"The system around him was very, very tight and compartmentalized," he said. "Few people knew about his movement and what he was doing."

In 1994, Mughniyah's brother was killed by a car bomb in Beirut, and reports at the time suggested Imad Mughniyah had been the target. A year later, FBI officials traveled to Saudi Arabia to take custody of him during a stopover of a Middle East Airlines flight from Khartoum, Sudan, to Beirut. But Saudi officials decided not to cooperate and refused to allow the plane to land, angering U.S. officials.

In one of the more dramatic episodes, Lebanese officials, exploiting a monitored telephone call, traced Mughniyah to Paris in 1985, only five months after the hijacking of a TWA jetliner, to which he had been linked. He was staying at the Hotel de Crillon, a luxurious hotel across the street from the U.S. Embassy. Tipped off by the Lebanese, U.S. officials asked French police to arrest him and turn him over. Instead, as previously reported in The Washington Post, French agents met with him several times over a six-day period, according to a source closely involved, and worked out an agreement to release him in return for the freedom of a French hostage.

Correspondents Griff Witte in Jerusalem and Thomas Erdbrink in Tehran and special correspondents Lynn Maalouf in Damascus and Samuel Sockol in Jerusalem contributed to this report.