The dismantlement of Syria’s chemical weapons arsenal has stalled.

Two deadlines for the removal of the deadliest toxins have passed but only about four per cent of the chemicals have left the country.

While there have been technical and logistical delays, intelligence sources maintain that Syria is intentionally delaying in order to keep its chemical capabilities for as long as possible.

In response, Israeli defence officials said that, despite the decision to end the distribution of gas masks in the country last month, the IDF Home Command still had 700,000 gas masks in storage and low-level production of new masks continues.

The agreement signed last year between the US and Russia to dismantle the massive Syrian chemical stockpile — believed to include more than 1,300 tonnes of sarin, mustard sulphur and VX nerve agents — set December 31 as the deadline for the removal of all “priority one” toxins and February 5 for “priority two” chemicals. Both of these deadlines have now passed and so far only two shipments of chemicals have left Latakia Port for destruction at sea.

Although a number of countries have contributed equipment, including heavy vehicles for the safe transportation of the chemicals and teams from the Organisation for the Prohibition of Chemical Weapons (OPCW) have been working in Syria for over four months, the regime has claimed that it will need more time to resolve logistical and security issues. While the Syrians are publicly still committed to the agreement, it is very unlikely now that the June 30 deadline — the date by which the entire arsenal was due to be dismantled — will be met.

The US ambassador to the OPCW, Robert Mikulak, said last week that “the effort to remove chemical agents and key precursor chemicals from Syria has seriously languished and stalled”.

Last week in Warsaw, US Defence Secretary Chuck Hagel said: “I do not know what the Syrian government’s motives are or why they are behind in delivering these materials”. And the growing feeling in the intelligence community is that the Syrians are playing for time.

The chemical weapons are a valuable bargaining chip for Assad in any future negotiations and could be used as a last-ditch weapon if the Syrian army is forced to retreat to the coastal enclave around Latakia, where many of the chemicals are being stored.

If Syria fails to comply with the agreement, the West’s options are limited. The US and its allies could go back to the UN Security Council for further sanctions but Russia and China are still opposed to any such move. Another option, reconsidering supplying the Syrian rebels with arms or even launching an attack on Syrian military targets, will run up against the same problems such plans faced in the past: the lack of unity within the Syrian opposition, the dominance of jihadis among the rebels and political opposition in the US and the UK.