BEIRUT — In Hezbollah's inner circle they called him "The One Who Never Sleeps."
Imad Mughniyah was one of the most hunted men in the world. Western security forces spent 25 years pursuing the Hezbollah warlord, the alleged mastermind of infamous attacks of the late 20th century and a pioneer of brutal tactics later emulated by Al Qaeda. In fact, he may have proved a more disciplined, effective master of asymmetric warfare than even Osama bin Laden.
Mughniyah survived through anonymity: changing hide-outs, moving without bodyguards or drivers, a pistol always in his belt. On the evening of Feb. 12, he left a safe house in the Kfar Soussa neighborhood of Damascus, a warren of nearly identical towers that house the employees and headquarters of Syria's vast intelligence apparatus.
He had just held a sit-down with a Syrian spy chief and was preparing for a secret meeting that night with President Bashar Assad, Western anti-terrorism officials say.
Seconds after Mughniyah got behind the wheel of his sport utility vehicle, an explosion incinerated him. The assassination in the heart of an authoritarian state ended his bloody odyssey through the modern history of terrorism.
His death at 45 remains as mysterious as his life. Interviews with anti-terrorism officials, diplomats and his associates reveal new details about the exploits of this secretive figure -- and about a slaying that may have been an inside job.
Mughniyah's role at the hub of a murky alliance of Hezbollah, Syria and Iran made him powerful but vulnerable, officials say. The likeliest scenario is that Israel eliminated him. But the aftermath has reinforced signs of potential Syrian involvement and exposed tensions among Syria, Iran and Hezbollah, Western officials say.
"What's troubling is that even if it was the Israelis, it happened in Damascus in a safe area meters from the office of [intelligence] chief Assef Shawkat," said a Western diplomat in the Syrian capital.
Iran and Hezbollah have sworn revenge, putting Israel on worldwide alert for the kind of attacks that were once Mughniyah's trademark.
Mughniyah sounded self-effacing in a rare interview he gave to a pro-Hezbollah newspaper not long before his death and published afterward.
"The Americans are making up stories about me and hold me responsible for a lot of attacks against them that happened around the world," he told Ibrahim al Amine of Lebanon's Al Akhbar. "Sometimes they think of me as if I have the key to the universe. It is difficult for them to understand that I am part of an institution that patiently plans and designs its moves."
Mughniyah had grown pudgy, his beard graying beneath round-rimmed glasses. He lived on the run among Iran, Syria and Lebanon and had two wives: a Lebanese in southern Lebanon and an Iranian in Damascus. He drove his own car, bought groceries alone and took catnaps while working nonstop, associates said. An associate in Damascus recalled how, during a heated group discussion, he curled up on a couch and went to sleep.
He oversaw foreign networks that he built after his terrorism campaign in Lebanon, including the 1983 bombings of the U.S. Embassy and Marine barracks. His cells allegedly carried out operations in France and Argentina, where two car bombings of Jewish targets left more than 100 dead. He also met in Sudan in the early 1990s with Osama bin Laden, whose militants got explosives training from Hezbollah experts.
Pursued by Israeli and U.S. forces, Mughniyah eluded several assassination attempts. His brother died in one attack in 1994; Mughniyah's bulletproof vest took multiple hits in another ambush.
In the late 1990s, Hezbollah curtailed attacks outside the Middle East. Mughniyah was an architect of a shift to concentrate on political and military activity in Lebanon. He served on the shura, the militia's leadership council, after being elected in 2001 under the alias Jawad Nur A-Din, Western officials say.
His post was secret, officials say, because Hezbollah claims to separate its political activity from its military wing, which is designated as a terrorist group by the United States and Israel.
Mughniyah's duties included aiding Palestinian militant groups with training and arms procurement, and running security for Hezbollah leader Sheik Hassan Nasrallah, to whom he was close, experts and associates say.
On May 13, 2006, he met in Lebanon with Hassan Zarkani, a representative of Iraqi Shiite strongman Muqtada Sadr, and agreed to provide smuggled anti-tank missiles to Iraqi fighters and train them in their use, Western anti-terrorism officials say.
But his prime obsession was the destruction of Israel. Hezbollah insiders and Israeli officials say that during the 2006 war in Lebanon, he ordered battlefield tactics that surprised Israeli troops with their ferocity and effectiveness.
"We saw death in their eyes," Mughniyah said of the Israelis, whose fighting skills he admired, according to Lebanese journalist Amine.