If the Air Force cheating scandal disclosed last week were a singular event, it would be easier to accept Pentagon assurances that America’s nuclear deterrence and military readiness have not been compromised. But it is the latest in a series of breaches that have raised alarms about discipline and competency in the Air Force.

On Wednesday, the Air Force said that 34 officers responsible for launching land-based nuclear missiles were pulled off the job and their security clearances suspended for cheating, or failing to report cheating, on tests that assess their knowledge of how to operate and launch nuclear weapons. They are based at Malmstrom Air Force Base in Montana, home to 150 Minuteman 3 intercontinental ballistic missiles. The cheating was discovered during an investigation into illegal drug possession in which 11 officers, including two accused in the cheating scandal, were under suspicion.

Air Force Secretary Deborah Lee James called the behavior “absolutely unacceptable” — as is the continuing pattern of misconduct. Last month, an Air Force inquiry revealed that the general who oversaw some of the nation’s nuclear weapons was dismissed for drunken antics during an official trip to Moscow last summer.

Last year, the service removed 17 officers assigned to stand watch over the missiles in Minot, N.D., after finding safety violations, potential violations in protecting codes and other problems. The setbacks for the nuclear mission go back to 2008, when there was an inadvertent cross-country transport of six nuclear-tipped missiles on a B-52 bomber whose pilot did not know they were aboard. Then Defense Secretary Robert Gates fired the top two Air Force officials, but problems have persisted.