Earlier this month, the Pentagon announced it was sending F-16s and Patriot missile batteries to Jordan, ostensibly for an exercise (“Eager Lion”), but which would remain in the Hashemite Kingdom afterward.

“It’s a clear, purposeful, presence of a strike force near the border of Syria,” the Israeli official noted. “I think it’s a message, a clear message.” The message is also meant to be legible to Iran, which is arming Syria and the Lebanese militia Hizballah by air, as well as testing the resolve of Western powers who threaten to strike its nuclear program. “It’s only a short leap to the Gulf,” the official said…

Behind the scenes, however, Israeli and U.S. military officials are coordinating how to target and destroy Assad’s arsenal of unconventional weapons under assorted scenarios, Israeli military and intelligence officials tell TIME. One scenario would be the sudden removal of Assad from the scene, be it by flight, death or if he simply disappears. That would prompt the allies to launch operations on the estimated 18 depots and other sites where WMDs are stored, the officials said. Search and destroy operations would also be launched if the weapons appeared to be about to fall into the hands of the rebels, which include Islamist extremists aligned with al-Qaeda.

The Israeli officials emphasized that it had not been decided whether both Israeli and U.S. forces would act, or who would do what. But the U.S. plans called for deploying forces on the ground as well as waves of airstrikes, to assure that the chemical and biological components are neutralized, according to the Israeli officials.