The Air Force's nuclear force is once again drawing negative attention after 34 launch officers have been stripped of their authority to control and launch nuclear-armed Minuteman III missiles because of their role in a cheating scandal at Malmstrom Air Force Base, Montana.

Investigators became aware that cheating was taking place on a monthly proficiency test because of another investigation that has already implicated 11 junior officers in using illegal recreational drugs.

Air Force Secretary Deborah Lee James and Air Force Chief of Staff Gen. Mark Welsh revealed the cheating scandal in a hastily called Pentagon news conference.

"This is absolutely unacceptable behavior and it is completely contrary to our core values in the Air Force," said James. Welsh characterized the cheating as potentially the largest such incident in the Air Force's history.

The 34 officers, ranging in rank from second lieutenants to captains, have been restricted from missile crew duty and have had their security clearances suspended while the investigation continues.

There are 600 launch officers responsible for operating the Air Force's fleet of 450 Minuteman III intercontinental ballistic missiles (ICBMs). Three bases are responsible for 150 of the missiles each, they are: Malmstrom AFB, in Montana; Minot AFB in North Dakota; and F.E. Warren AFB in Wyoming.

The launch officers spend 24 hours shifts in underground launch centers where they are responsible for ICBM missiles based in missile silos in the surrounding countryside.

Welsh said that the investigation determined that the officers had "electronically shared" answers via text messages for the monthly proficiency test conducted in August and September. Seventeen of the officers were directly involved in the cheating while the others were aware of it but did nothing about it.

As a result of the cheating, the Air Force has begun re-testing all 600 of its ICBM officers. The decertification impacts 34 of the 190 nuclear missile officers at Malmstrom.

Both James and Welsh said that the episode was counter to the Air Force's emphasis on integrity. James said she had confidence in the Air Force's nuclear force because "this was a failure of some of our airmen. It was not a failure of the nuclear mission."

Defense Secretary Chuck Hagel visited F.E. Warren AFB last Thursday to stress the importance of the Air Force's nuclear mission and praise the force's professionalism. But his visit was overshadowed by the disclosure that two launch officers at Malmstrom had been implicated in the illegal drug investigation.

Thursday's disclosure of the cheating scandal at Malmstrom was the latest in a string of negative incidents that have taken place in the Air Force nuclear mission.

In mid-December, it was revealed that Major General Michael Carey, who commanded the three Air Force wings responsible for the ICBM's had been disciplined for drinking excessively while attending a nuclear mission conference in Moscow. Carey had been relieved of his command in October after the Air Force Inspector General investigated allegations about his drunken behavior.

In November, the Associated Press reported on an internal Air Force report that found low morale and disciplinary problems within the Air Force's nuclear force. Air Force officials said newer data indicated that negative trendlines had improved over the past year.

In October, it was revealed that four Air Force officers had been disciplined for two incidents earlier in the year where they had fallen asleep during their 24 hour shifts in the process leaving open the blast security door intended to keep out intruders. Launch officers are allowed to take naps as long as one of the two officers on duty remains awake, but in each case both were asleep.

In April, 17 launch officers at Minot AFB lost their launch authority and had to be retrained after their poor performance during a recent inspection.

Jacquelyn Martin/AP Photo