The unanimous official, who spoke to NYT, said that Israel had been tracking Abzar for years, and had wanted to assassinate him over his prominent role in Syria's weapons program even before the outbreak of the civil war in 2011.
Syria on Tuesday accused Israel of assassinating a top Syrian rocket scientist over the weekend, heightening the growing tensions between the two countries as Syrian government troops restore control over areas bordering Israel.
Aziz Asbar, the scientist killed in the bombing, held top-level positions in weapons manufacturing research, with allegations of heading a chemical weapons project that was used against civilians in rebel-held towns in Syria. He was also collaborating with Iranian Maj.
"Every day in the Middle East there are hundreds of explosions and settling of scores".
The Israelis believed Asbar led a secret unit called Sector 4 which aimed to develop precision-guided missiles in Syria which could threaten Israel.
If the assassination was carried out by Mossad, it was the latest in a long line of Israeli attacks targeting Syrian weapons capabilities and development. The attack, which took place in Masyaf, was at least the fourth assassination mission by Israel in three years against an enemy weapons engineer on foreign soil. The official said Mossad had been tracking Asbar, who was allegedly in charge of re-building an underground weapons factory that the Israeli military destroyed past year. The SSRC's facility in Masyaf, allegedly involved in the production of non-conventional arms as well as medium- and long-range scud missiles, has been targeted multiple times over the past year by air strikes blamed on Israel.