Former CIA Official: Israeli Mossad behind Mugniyah Killing

Riedel, who spent over 30 years with the CIA before serving as a senior advisor on South Asian and Middle East affairs under three US presidents, said Israel has already carried out similar operations in Syria.

Currently a senior fellow with the Saban Center for Middle East Policy at the Brookings Institute, he says Mugniyah's assassination proves Israel has successfully infiltrated Hizbullah and that even Secretary General Hassan Nasrallah knows he may also be in the crosshairs.

"Israeli intelligence services have motive and they have proven their ability to strike in Damascus in the past. This is a significant operation, whether or not the Israelis want to publicly admit to it. He (Mugniyah) has topped the US and Israel's most-wanted list for a quarter of a century," said Riedel.

The seasoned intelligence official said he believes Mugniyah was not the only name on a possible hit list. "It definitely includes Hassan Nasrallah," he said, "the Mossad is looking for Nasrallah and he knows it, that's why he conducts his operations from underground."