U.S.'s Mattis says 'zero intelligence' that rebels in Syria's Idlib have chemical weapons capability

Syria - Mattis Lacks State Department's Intelligence ... On Al-Qaeda's Chemical Capabilities

Moon of Alabama,

6 September, 2018

The U.S. Secretary of Defense seems to lack the intelligence the UN and the U.S. Department of State obviously have.

U.S.'s Mattis says 'zero intelligence' that rebels in Syria's Idlib have chemical weapons capability

New Delhi (Reuters) - There was “zero intelligence” of chemical weapons capabilities possessed by groups opposing Syrian President Bashar al-Assad in the province of Idlib, U.S. Defence Secretary Jim Mattis said, adding that the facts did not back Russian assertions.
...
“We have zero intelligence that shows the opposition has any chemical capability,” Mattis told reporters traveling with him to the Indian capital of New Delhi.
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“We have made very clear that by putting out innuendo that somehow any chemical weapon use coming up in the future could be ascribed to the opposition, well, we want to see the data,” Mattis said. “We cannot see anything that indicates the opposition has that capability.”

On October 18 2017 the U.S. State Department issued a travel warning for Syria:

It says in the third paragraph (pic):

Terrorist and other violent extremist groups including ISIS and al-Qa’ida-linked Hayat Tahrir al-Sham (dominated by al-Qa’ida affiliate Jabhat al-Nusrah, a designated Foreign Terrorist Organization), operate in Syria. In July 2017, Hayat Tahrir al-Sham consolidated power in Idlib province after it clashed with other armed actors. [...] Tactics of ISIS, Hayat Tahrir al-Sham, and other violent extremist groups include the use of suicide bombers, kidnapping, small and heavy arms, improvised explosive devices, and chemical weapons. ...

The UN also knows of and is similar concerned about Hayat Tahrir al-Sham's chemical weapon capabilities. During a press conference on August 30 the UN Special Envoy for Syria, Staffan de Mistura, explicitly discussed these:

So, the issue of avoiding the potential use of chemical weapons is indeed crucial and would be totally unacceptable. We all are aware that both the government and al-Nusra have the capability to produce weaponised chlorine, that’s the one people are talking about, not sarin. Hence an increased concern by all of us, and everyone else, and alert.

There is no doubt that HTS and other such groups have chemical capabilities. They do.

Why is Mattis lying about it?