The US intelligence chief just acknowledged a major failure of the Syria chemical-weapons deal

James Clapper, the US director of national intelligence, told a Senate committee Tuesday that the Syrian government isn't being entirely transparent about its chemical-weapons program and that Damascus has used chlorine against anti-regime rebels.

That is despite the regime of Syrian President Bashar al-Assad joining the Chemical Weapons Convention and agreed to the removal and destruction of its chemical weapons stockpile.

They did so to avoid a threatened US bombing campaign following the August 21, 2013, sarin-gas attack on Ghouta, outside the country's capital of Damascus. The attack left some 1,400 people dead.

In August of 2014, the Obama administration declared that Syria's chemical stockpile had been destroyed, a development that President Barack Obama said "advances our collective goal to ensure that the Assad regime cannot use its chemical arsenal against the Syrian people," according to The Washington Post.

But Clapper complicated this premise in a single, brief paragraph.

"We assess that Syria has not declared all the elements of its chemical-weapons program to the Chemical Weapons Convention (CWC)," Clapper said in his congressional testimony. "Despite the creation of a specialized team and months of work by the Organization for the Prohibition of Chemical Weapons (OPCW) to address gaps and inconsistencies in Syria's declaration, numerous issues remain unresolved."

Syria has carried out chemical weapons attacks even after the implementation of the September 2013 agreement, he said.

"We continue to judge that the Syrian regime has used chemicals as a means of warfare since accession to the CWC in 2013," Clapper said.

He noted OPCW investigators' conclusion that "chlorine had been used on Syrian opposition forces in multiple incidents in 2014 and 2015." The regime was still dropping chlorine bombs from the air. "Helicopters - which only the Syrian regime possesses - were used in several of these attacks," Clapper stated.

Chlorine attacks have been documented in Syria throughout 2014 and 2015, while one group of Syrian doctors discovered at least 31 chlorine attacks in the country during a single 10-week span in 2015.

And it's long been clear that at least some of Syria's chemical-weapons infrastructure remained in place past mid-2014. According to a July 2015 Wall Street Journal report, US intelligence agencies "concluded that the regime didn't give up all of the chemical weapons it was supposed to," while Assad "continu[ed] to operate weapons-research facilities."

Clapper's statement is a straightforward acknowledgment that the chemical-weapons deal didn't fully accomplish its purpose. The Assad regime did join the CWC, and give up the entirety of its known chemical weapons stockpile. The deal left Assad far less capable of carrying out a Ghouta-style attack, and it was accomplished without actual US military action.

At the same time, Assad retained a chemical-weapons infrastructure and continued to use chlorine on the battlefield - all while avoiding any US or allied military consequences for crossing Obama's supposed "red line."