AFTER PROLONGED CONFUSION, we may have some clarity on what caused the emergency restriction on the airspace around El Paso International Airport: Someone used a sophisticated anti-air laser against what they thought was a drone launched from Mexico, but turned out to be a party balloon. Understandably, the first suspects were the Army units at Fort Bliss, which abuts El Paso and the airport. But it wasn’t the Army that fired the weapon.

According to the New York Times, Customs and Border Protection personnel fired an experimental anti-drone laser on loan from the Department of Defense at what they thought was a cartel drone—without sufficient coordination with the Federal Aviation Administration. That prompted the FAA to shut down the airspace around the airport up to 18,000 feet in an extraordinary emergency move.

But focusing on the harmlessness of the target obscures the deeper issue: Why was this weapon employed without the discipline that governs every legitimate use of force in the military?

Fort Bliss sits on the edge of El Paso. While it’s a large post, and it has a very isolated desert training area, it borders a large city with hospitals, businesses, highways, civilian neighborhoods, and a relatively large international airport.