WASHINGTON (AP) — Another embarrassing stumble by the U.S. nuclear missile force, this time a safety and security inspection failure, is raising questions about the Air Force’s management of arguably the military’s most sensitive mission.

The head of nuclear air forces, Lt. Gen. James Kowalski, revealed to The Associated Press on Tuesday that the 341st Missile Wing at Malmstrom Air Force Base in Montana had failed what the military calls a “surety” inspection. That’s a formal check on the unit’s adherence to rules ensuring the safety, security and control of its nuclear weapons.