A retired general chosen to explore flaws in U.S. nuclear forces signed off one year ago on a study describing the nuclear Air Force as "thoroughly professional, disciplined" and performing effectively.

Senior Air Force leaders interpreted that assessment as an encouraging thumbs-up.

The overall judgment conveyed in the April 2013 report by a Pentagon advisory group headed by retired Gen. Larry Welch appears to contradict the picture that has emerged since of a nuclear missile corps suffering from breakdowns in discipline, morale, training and leadership.

It's unclear whether the Air Force took an overly rosy view of the Welch assessment, which was not uniformly positive, or whether his inquiry missed signs of trouble documented in recent months in a series of Associated Press reports.