The Defense Department has reversed its previous statement that ISIS used chemical weapons against US troops during an encounter on Sept. 20. Pentagon spokesman Navy Capt. Jeff Davis told reporters during a briefing on Wednesday that a “series of follow-on tests” concluded “it was not sulfur mustard.” No US troops were injured in the attack, which Chairman of the Joint Chiefs of Staff Gen. Joseph Dunford had previously characterized as deploying “a blistering mustard agent,” and Davis said the Defense Department was unaware of ISIS making any use of chemicals weapons since then. “That said, we recognize that ISIL has used them on multiple occasions on both sides of the border and we should expect it’s a very real threat we will face as we continue to progress,” he said.
The U.S. military is maintaining a beefed-up presence in the Middle East, including fighters and air defense assets, following the U.S. strikes on Iranian nuclear facilities June 22 and subsequent retaliation by the Iranians against Al Udeid Air Base in Qatar.