* Rebels, Hezbollah seen unlikely to grab disarmament trucks
* Israelis worry Assad to retain some of his toxic arsenal
By Dan Williams
TEL AVIV, Jan 14 (Reuters) - Internationally-monitored convoys removing Syrian chemical weapons are at little risk of being seized by rebels fighting President Bashar al-Assad or by his Lebanese Hezbollah allies, a senior Israeli military officer said on Tuesday.
The estimate suggested that Israel, which repeatedly bombed targets in Syria last year to prevent suspected transfers from Assad's arsenal to hostile guerrillas, was holding fire as tonnes of toxins are trucked out - in some cases through war zones not under Assad's control.
"We are not poised for a situation in which a convoy encounters rebels. This is something being addressed by the international forces that are there," the officer told Reuters, referring to the Organisation for the Prohibition of Chemical Weapons (OPCW), which is overseeing the disarmament process.
He assessed the OPCW's role would also prevent Hezbollah, which has fighters in Syria helping Assad battle an almost three-year-old rebellion, from redirecting trucks to Lebanon.
"I reckon such a scenario is not possible," said the officer, who declined to be named under military secrecy.
Syria agreed to abandon its chemical weapons by June under a deal worked out by Russia and the United States after an Aug. 21 sarin gas attack near Damascus that Western nations blamed on Assad forces. The government blames rebels for the attack.
Around 1,300 tonnes of Syrian chemical weapons are slated for decommissioning. Some are to be shipped from Latakia port for destruction on a specially converted U.S. vessel.
Syria loaded a first batch of chemicals onto a Danish cargo vessel last Tuesday, a week after missing the original Dec. 31 target to ship out all the deadliest chemicals. The OPCW has called on Assad's government to speed up the process. An official contacted by Reuters on Tuesday declined to say whether any further cargoes had been loaded onto ships.
ENTIRE ARSENAL OUT?
Israel is an old enemy of Syria under Assad's family, and of Hezbollah, but also feels threatened by the Islamist-led rebels. It has welcomed the stripping of Syria's chemical arsenal while warning world powers that Damascus could renege.
"We are very preoccupied by places (in Syria) where - perhaps - the weapons have not been dismantled, and remain, and may end up in Lebanon," the Israeli officer said, without elaborating. "We are looking very closely for this, and we really do not want it to happen."
Iranian-backed Hezbollah, which has tens of thousands of rockets as well as riflemen, fought Israel's technologically superior forces to a standstill in a 2006 border war and poses its most immediate threat. But some Israeli officials doubt the militia would try to obtain chemical weapons.
Regional security sources said that on at least three occasions last year Israel bombed convoys or depots in Syria that it believed held advanced weapons destined for Hezbollah.
Israel has not formally confirmed carrying out those raids, which drew retaliation threats from Damascus. While not commenting on specific actions, the Israeli officer acknowledged that intervening militarily now could upset a disarmament campaign coordinated by numerous foreign powers.
"I know that, as of now, no convoy has been harmed. I don't know what will happen tomorrow, but I am not preparing for a situation in which I would be the one 'protecting' these convoys," the officer said.
Asked if the possibility of inadvertently harming foreigners accompanying the convoys might stay Israel's hand, the officer said: "Yes, unequivocally."
"We very much do not want to undermine this process of the chemical weapons being dismantled. It is a dramatic event in terms of Israel's security outlook. It is, without a doubt, an achievement." (Additional reporting by Dominic Evans in Beirut, editing by Mark Heinrich)