The West may be forced to seize Bashar al-Assad's weapons of mass destruction including toxic gas stockpiles, according to the Daily Telegraph newspaper Thursday.

International troops could be forced to intervene in Syria if the collapse of President Bashar al-Assad's regime were to leave the stockpiles of his chemical weapons vulnerable to terrorists, western diplomatic sources have told the paper.

Like Israel, Syria has not signed the Chemical Weapons Convention of 1997, nor is it a member of the Organisation for the Prohibition of Chemical Weapons, which verifies stockpiles of these weapons.

Syria possesses hundreds of tons of VX, Sarin and mustard gas.

Western governments are concerned about the security of these munitions if Assad's regime falls or loses control over the relevant sites.

"The thing that privately has got people very worried is chemical weapon stocks," said the diplomat.

"Were it to be the case that the regime did start to lose control of the security environment, and it looked as though it wasn't able to secure those sites, then that would be a game-changer." At present, the 14-month uprising probably does not pose an "existential threat" to the regime, added the diplomat.

But if that changed, the international community would have to avert the threat of chemical weapons falling in dangerous hands.

Al-Qaeda, which has been blamed for recent suicide bombings in Syria, is understood to have moved operatives into the country from neighbouring Iraq.

Hizbollah has a longstanding presence in Syria and a close alliance with Assad, the newspaper reported.

"We could not tolerate the possibility of some of that stuff falling into the wrong hands," said the diplomat.

"This uprising is not an existential threat to the Assad cartel, but if it was the case that they were starting to lose the plot and it looked as if their ability to secure those materials was questionable, then I think you'd see more very serious worries coming out of the Security Council." Outside experts say that Syria's chemical weapons programme dates back to the 1970s and ranks among the most advanced in the Middle East. However, Assad is not believed to possess any biological weapons.

The rationale for his arsenal is to counterbalance a nuclear-armed Israel on Syria's western flank and a NATO-allied Turkey on the northern frontier.

Experts believe Assad is highly unlikely to use these munitions against his domestic opponents, the Telegraph said.

Whether Syria's armed forces are fully trained in their use is also "questionable".

Dina Esfandiary, a non-proliferation specialist at the International Institute for Strategic Studies here, said that little was known about the full extent of Syria's chemical weapons stockpiles.

"It's worrying because we don't know," she said. "We don't know exactly what Syria's capability is.

We don't know how big their stockpiles are - or where they are. It would be difficult for everybody to secure them, particularly if factions within the country are fighting each other." Syria maintains and continues to upgrade a chemical weapons programme", according to Jane's Intelligence Review.

Syria "continues to enhance its ability to deliver both conventional and chemical warheads." The country is believed to possess 700 Scud missiles, one of the biggest such arsenals in the Middle East.

The evidence suggests that Syria has adapted these weapons to deliver chemical warheads.
In 2007, an explosion at another plant killed 15 scientists and engineers as they tried to load a chemical warhead on to a Scud.

North Korea is known to have helped Syria's missile programme and may have aided the development of chemical weapons, the paper continued.