When the news reported that Imad Mughniyah was assassinated I was stunned. This is equivalent to killing Bin Laden. Except that locating and successfully executing an attack on "Mughsy" was a much more difficult task.
To say he had a heightened security posture would be the understatement of the year. He is/was the mythological equivalent of the unicorn, something that has always been talked about but never actually seen. To illustrate this point, most of the pictures Mughniyah were taken very early in his life (his late teens/early 20s... he is now roughly 45). He was vital to Iranian interests in Lebanon because he was someone the Iranians could depend on to execute Tehran's will. He demonstrated that back in 1983 when he orchestrated the Marine Corps Barracks bombing. He was vital to Hezb'allah because of his trusted status with Tehran and the weapons, finance, and training they provided.
In essence, he was an important bridge between Iran and Hezb'allah.
He is someone the Iranians depended on for over 20 years and the kind of trust and stability he provided to the regime in Tehran and to Hezb'allah in Lebanon will be difficult to replace. Given his senior position within Hezb'allah and the organization's acting as Damascus' proxy in fighting Israel, this would also be a significant setback for Syria as well (not to mention a huge embarrassment to the government, because it happened in their capital).
For decades, he was protected by the Iranian/Syrian governments and Hezb'allah's own considerable intelligence apparatus. His death is an intelligence coup that may not be matched for many, many years to come. Assuming the press coverage is right, what does his assassination portend?
To capture the essence of the "red" line that has been crossed by his assassination, one must understand there were other opportunities to capture him alive, but those nations thought the price was too high and balked. For instance, there are reliable press reports that the French government knew about his entry into their country (and that French intelligence agents actually spotted him) in the mid 1980's and did nothing to apprehend him. In April 1995, FBI agents got a tip that Mughniyah was on a Middle East Airlines (MEA) flight from Sudan that was being routed through Saudi Arabia before moving on to Beirut. Agents waited for him to land at the Saudi airport, but Saudi authorities, realizing the potential problems of his apprehension in the Kingdom, refused to let the MEA flight land in Saudi Arabia. This thwarted our ability to apprehend him. In both of these cases, the likely reason for their balking on arresting him is the retaliatory attacks that would ensue until he was released.
From Hezb'allah's view point, a "red" line has been crossed and the organization will look for vengeance. The most reliable barometer of Hezb'allah's reaction to this will depend if Israel is somehow held accountable for this action. When Israel killed Hezb'allah Secretary General Abbas Musawi in February 1992, the Israeli Embassy in Buenos Aires, Argentina was destroyed a few weeks later. This 1992 attack was claimed by Hezb'allah's terrorist wing, the Islamic Jihad Organization, in retaliation for Musawi's death. If Mughniyah is indeed dead and Israel is held responsible, the clock is ticking. Hezb'allah will retaliate for this. Bank on it. If history provides any benchmark, look for a spectacular event in the very near future. As stated in my previous pieces, Hezb'allah has extensive contingency plans for this sort of occurrence and can put "steel on target" in short order.
No doubt, US intelligence agencies are preparing a slew of threat assessments based on his death and what is likely to occur and where it is likely to occur. Once Hezb'allah/Syria/Iran figure out who is responsible for this, they will all work together and retaliate.
I have absolutely no remorse for his death, he got what he deserved. That being said, in the minds of many in Islamic resistance circles, Mughniyah is a legend and his death will not be taken lightly.