The Air Force has suspended security clearances for 34 officers and is re-testing the entire force overseeing America's nuclear-armed missiles after uncovering widespread cheating on a key proficiency exam.
The incident was the largest single case of cheating in America's nuclear missile wings in memory, and is the latest embarrassment for a force that faces growing questions over discipline and morale in the post-Cold War era.
The head of the ICBM force, Air Force Major General Michael Carey, was fired in October for getting drunk and carousing with women while leading a government delegation to Moscow for talks on nuclear security.
The latest incident occurred last year and involved sharing answers by text message on a monthly proficiency exam for missile launch officers at Malmstrom Air Force Base in Montana, Welsh said.
Malmstrom is one of three bases responsible for the United States' 420 nuclear-armed intercontinental ballistic missiles.
"There was cheating that took place with respect to this particular test. Some officers did it. Others apparently knew about it, and it appears that they did nothing, or at least not enough, to stop it or to report it," Air Force Secretary Deborah Lee James said at a news conference.
Welsh said the 34 individuals under investigation were no longer certified to do their jobs and their security clearances were suspended.
"They are restricted from missile crew duty," Welsh said, adding "people at every level" would be held accountable.
Welsh said retesting of their entire missile crew of around 600 officers, ranging in ranks from 2nd lieutenants to Air Force captains, would be completed by Thursday and the exam results would be made available to the public.
Both Welsh and James stressed they had full confidence in the security of America's nuclear missile force.
"This is not about the compromise of nuclear weapons. It's about compromise of the integrity of some of our airmen," he said.
But the cheating scandal was only the latest embarrassment for the U.S. nuclear missile force and, more broadly, the Air Force.
The nuclear missile wing at the base where the cheating took place made news for failing an Air Force inspection last August.
Last week, the Air Force revealed that 10 Air Force officers at six bases were being investigated for alleged illegal drug possession. The Air Force on Wednesday said another officer was also being investigated.
Two of them were also implicated in the cheating scandal.
As for Carey, he was removed from his job as commander of the 20th Air Force in October for "conduct unbecoming a gentleman" during a trip to Russia last year.
According to an investigation by the Inspector General of the Air Force, Carey drank steadily throughout the trip, stayed out late with women he met in Moscow, and showed up 45 minutes late for an early morning departure for delegation meetings.
Carey was said to be slurring his words on a delegation trip to a local monastery and asked repeatedly for a chance to sing with a Beatles cover band at a Mexican restaurant.
The Air Force has sought to tighten controls over its nuclear weapons after a 2008 incident in which a B-52 bomber accidentally transported nuclear armed missiles across the country, leading to the ouster of then-Air Force Secretary Michael Wynne and General T. Michael Moseley, the top uniformed officer in the Air Force.