" (Reuters) - Increasingly under pressure by rebels intent on unseating him, Bashar al-Assad has considered using chemical weapons against his enemies but Washington and Moscow have formed an unlikely alliance to force him to abandon such plans.
Analysts and diplomats across the region and beyond do not doubt that the Assad government, recoiling from a devastating attack on its security establishment last week and struggling to contain rebel offensives across Syria, is capable of using agents such as Sarin gas if its survival is at stake.
Yet some believe that the government's unprecedented admission that it possesses a chemical stockpile - although in safe storage and only to be deployed against "external aggressors" - is an attempt to allay international alarm that might prompt outside intervention to secure the weapons.
"They have a keen instinct for regime survival and this is an issue which didn't play well for them, which would really bring serious consequences, not the type of stuff we have been seeing so far from the international community," said Salman al-Shaikh of the Brookings Doha center.
"I think they wanted to move quickly to take us away from that, to reassure in many ways.
"This regime is capable of anything, but in this case it felt there may well be consequences, that they are perhaps crossing some red lines.".....
One Western diplomat in the region said: "There was talk of them using it two weeks ago, but the Russians intervened quickly to stop him.
"If you think how desperate these people are and what they have done in the past, you have to assume they would be prepared to use it. All of us think he (Assad) is capable of using it and will do it if he was pushed to the wall," the diplomat said, referring to credible reports that Assad was preparing to use Sarin gas against Syrian rebels.
But "the Russians got hold of him and told him ‘don't even think about it'".
Moscow went further on Monday, publicly warning Assad not to use chemical weapons, which it said was barred by Syria's 1968 ratification of an international protocol against using poison gas in war......
The diplomat believes Syria's statement, by foreign ministry spokesman Jihad Makdissi, was put out at Russia's insistence......
Some Western intelligence sources suggested that Hezbollah and Iran's Revolutionary Guards, both close allies of Syria, have sent some special units to back Assad in his fight against Sunni insurgents and might get hold of the chemical weapons in the case of a total collapse of government authority...."