In the spring of 2015 a Syrian major general escorted a small team of chemical weapons inspectors to a warehouse outside the Syrian capital Damascus. The international experts wanted to examine the site, but were kept waiting outside in their car for around an hour, according to several people briefed on the visit.

When they were finally let into the building, it was empty. They found no trace of banned chemicals.

“Look, there is nothing to see,” said the general, known to the inspectors as Sharif, opening the door.

So why were the inspectors kept waiting? The Syrians said they were getting the necessary approval to let them in, but the inspectors had a different theory. They believed the Syrians were stalling while the place was cleaned out. It made no sense to the team that special approval was needed for them to enter an empty building.

The incident, which was not made public, is just one example of how Syrian authorities have hindered the work of inspectors and how the international community has failed to hold Syria to account, according to half a dozen interviews with officials, diplomats, and investigators involved in eliminating Syria’s weapons of mass destruction.

A promise by Syria in 2013 to surrender its chemical weapons averted U.S. air strikes. Many diplomats and weapons inspectors now believe that promise was a ruse.

They suspect that President Bashar al-Assad’s regime, while appearing to cooperate with international inspectors, secretly maintained or developed a new chemical weapons capability. They say Syria hampered inspectors, gave them incomplete or misleading information, and turned to using chlorine bombs when its supplies of other chemicals dwindled.

There have been dozens of chlorine attacks and at least one major sarin attack since 2013, causing more than 200 deaths and hundreds of injuries. International inspectors say there have been more than 100 reported incidents of chemical weapons being used in the past two years alone.

“The cooperation was reluctant in many aspects and that’s a polite way of describing it,” Angela Kane, who was the United Nation’s high representative for disarmament until June 2015, told Reuters. “Were they happily collaborating? No.”

“What has really been shown is that there is no counter-measure, that basically the international community is just powerless,” she added.

That frustration was echoed by U.N. war crimes investigator Carla del Ponte, who announced on Aug. 6 she was quitting a U.N. Commission of Inquiry on Syria. “I have no power as long as the Security Council does nothing,” she said. “We are powerless, there is no justice for Syria.”

The extent of Syria’s reluctance to abandon chemical weapons has not previously been made public for fear of damaging international inspectors’ relationship with Assad’s administration and its backer, Russia, which is giving military support to Assad. Now investigators and diplomatic sources have provided telling details to Reuters:

– Syria’s declarations about the types and quantities of chemicals it possessed do not match evidence on the ground uncovered by inspectors. Its disclosures, for example, make no mention of sarin, yet there is strong evidence that sarin has been used in Syria, including this year. Other chemicals found by inspectors but not reported by Syria include traces of nerve agent VX, the poison ricin and a chemical called hexamine, which is used to stabilise sarin.

– Syria told inspectors in 2014-2015 that it had used 15 tonnes of nerve gas and 70 tonnes of sulphur mustard for research. Reuters has learned that inspectors believe those amounts are not “scientifically credible.” Only a fraction would be needed for research, two sources involved in inspections in Syria said. Continue reading.