The United States and Jordan have launched a 12-day military exercise with scenarios ranging from border security to counter-terrorism and for the first time a simulated chemical incident.

The Eager Lion drill started Sunday, a day after the U.S., France and Britain launched missiles at Syrian military targets in response to an alleged chemical weapons attack near Damascus a week ago.

Maj. Gen. Jon Mott, the director of Exercises and Training at the U.S. Central Command, told reporters that a mobile laboratory team will respond to a simulated chemical incident.

He said that it’s a “threat all too real, as we’ve seen recently in Syria.”

More than 7,000 troops, including 3,500 U.S. service members, are participating in the annual drill, the U.S. military’s largest and most complex in the region.

(AP)