Syria suspected Israel of carrying out the 2008 murder of a top security aide of President Bashar al-Assad, according to US diplomatic cables leaked by WikiLeaks and published by the Guardian on Tuesday.
The suspicion weakened the case for continuing indirect peace negotiations with the Jewish state that was being put forward by Assad and others within the Syrian government and played into the hands of hardliners, the cables said.
They said that Brigadier General Mohammed Sleiman, a shadowy figure whose assassination by a sniper in the coastal city of Tartus on August 1, 2008 Syria kept under wraps for days, was a top "presidential security aide."
"Sleiman enjoyed a reputation among embassy contacts as having special status and proximity to Bashar," one leaked cable said.
"Sleiman was said to have managed special projects for Assad, some of which may have been unknown to the broader Syrian military leadership."
His assassination came just 11 months after an Israeli air strike deep inside Syrian territory destroyed a still shadowy facility that may have been one of the special projects that Sleiman managed.
The desert plant in Deir al-Zor province in northeastern Syria has been the focus of allegations that Damascus was pursuing a nuclear programme with North Korean assistance which have since been under investigation by the UN watchdog, the International Atomic Energy Agency.
The US cable said that Syria went to immense lengths to keep Sleiman's killing under wraps.
"Syrian security services quickly cordoned and searched the entire beach neighbourhood where the shooting had occurred," it said. "Syria-based reporters are under instructions not to report the story."
It was only on August 6 and after mounting speculation in the Arab and Israeli media that the government put out a short statement.
"Sleiman, an officer of the Syrian Arab Army has been assassinated. An investigation is underway," the statement said.
The leaked US cable on the killing said "the most obvious suspects are the Israelis."
"SARG (Syrian Arab Republic Government) security services are well aware that the coastal city of Tartus would offer easier access to Israeli operatives than would more inland locations such as Damascus," it said.
"Sleiman was not a highly visible government official, and the use of a sniper suggests the assassin could visually identify Sleiman from a distance."
The cable suggested Syria "may be reluctant to level public accusations as (1) they may not know who did it; (2) such accusations could impair or end Syria's nascent peace negotiations with Israel; and (3) publicising the event would reveal yet another lapse in Syria's vaunted security apparatus."
The timing of the killing as the Syrian president was on a visit to Iran was also uncomfortable as its key regional ally opposed the Turkish-brokered peace feelers Syria had launched with Israel in May that year.
"Coinciding with Bashar's trip to Tehran and on the heels of the latest round of indirect talks with Israel, the assassination will likely weaken advocates of the peace negotiations, including Bashar himself," it said.
A second leaked cable reported by Britain's Guardian newspaper cited a US embassy contact as saying that the killing had become "a frequent source of controversy" in internal Syrian government deliberations.
"Underlying this tense exchange was frustration within the security services that the SARG was all but ignoring the assassination of Suleiman. Security service officials were suggesting that 'if the Israelis did it', why was the Syrian government continuing the dialogue?"
The indirect peace negotiations finally broke off in December 2008 when Israel launched a devastating offensive against the Gaza Strip, run by the Palestinian Islamist movement Hamas, another Damascus ally.