A nuclear missile base security force failed a drill last summer because they were unable to speedily regain control of the captured nuclear weapon, according to an internal Air Force review obtained by The Associated Press.

The previously unreported failure, which the Air Force called a "critical deficiency," was the reason the 341st Missile Wing at Malmstrom Air Force Base in Montana flunked its broader safety and security inspection, the AP reported.

The security team was required to respond to the simulated capture of a Minuteman 3 nuclear missile silo, termed an "Empty Quiver" scenario in which a nuclear weapon is lost, stolen or seized, according to the AP.

Each of the Air Force's 450 Minuteman 3 silos contains one missile armed with a nuclear warhead and ready for launch on orders from the president, the AP reported. The inspection failure was one of a string of nuclear missile corps setbacks revealed by the AP over the past year.

The force has suffered embarrassing leadership and training lapses, breakdowns in discipline and morale problems, the AP reported.

Earlier this year, Defense Secretary Chuck Hagel ordered two parallel nuclear reviews, still underway, to address his concern that these lapses could erode public trust in the security of the nation's nuclear weapons, according to the AP.

When the Air Force publicly acknowledged the inspection failure in August, it said "tactical-level errors" had been committed during one phase of the inspection, but it did not say the errors were made by security forces, the AP reported.

At the time, the Air Force declined to provide details, saying to do so could expose potential vulnerabilities. Security forces, safety officers, logistics teams, missile launch crews and others participated in the Malmstrom inspection, according to the AP.

"We cannot divulge additional details of the scenario or the response tactics due to it being sensitive information that could compromise security," Sheets said, adding that all "countermeasures," or corrective actions have been accomplished.

The partially censored document provided to the AP describes in broad terms the nature of the inspection failure, its significance and its underlying causes. It said insufficient training was at the heart of the problem, beginning with a lack of familiarity among the security forces with "complex scenario" exercises.

The report also cited unspecified shortcomings in "leadership culture" and a lack of standardized simulations, according to the AP.