Trouble inside the US Air Force's nuclear missile force runs deeper and wider than officials have let on.



An unpublished study for the Air Force, obtained by The Associated Press, cites "burnout" among launch officers with their fingers on the triggers of 450 weapons of mass destruction. Also, evidence of broader behavioural issues across the intercontinental ballistic missile force, including sexual assaults and domestic violence.



The study, provided to the AP in draft form, says that court-martial rates in the nuclear missile force in 2011 and 2012 were more than twice as high as in the overall Air Force. Administrative punishments, such as written reprimands for rules violations and other misbehaviour, also were higher in those years.



These indicators add a new dimension to an emerging picture of malaise and worse inside the ICBM force, an arm of the Air Force with a proud heritage but an uncertain future.



Concerned about heightened levels of misconduct, the Air Force directed RAND Corp, the federally funded research house, to conduct a three-month study of work conditions and attitudes among the men and women inside the ICBM force. It found a toxic mix of frustration and aggravation, heightened by a sense of being unappreciated, overworked and at constant risk of failure.



Remote and rarely seen, the ICBM force gets little public attention. The AP, however, this year has documented a string of missteps that call into question the management of a force that demands strict obedience to procedures.



The AP was advised in May of the confidential study, shortly after it was completed, by a person who said it should be made public to improve understanding of discontent within the ICBM force. After repeated inquiries and shortly after AP filed a Freedom of Information Act request for a PowerPoint outline, the Air Force provided it last Friday and arranged for RAND officials and two senior Air Force generals to explain it.



Based on confidential small-group discussions last winter with about 100 launch officers, security forces, missile maintenance workers and others who work in the missile fields - plus responses to confidential questionnaires - RAND found low job satisfaction and workers distressed by staff shortages, equipment flaws and what they felt were stifling management tactics.



It also found what it termed "burnout".



Burnout in this context means feeling exhausted, cynical and ineffective on the job, according to Chaitra Hardison, RAND's senior behavioural scientist and lead author of the study. She used a system of measure that asks people to rate on a scale of 1 to 7 - from "never" to "always" - how often in their work they experience certain feelings, including tiredness, hopelessness and a sense of being trapped. An average score of 4 or above is judged to put the person in the "burnout" range.



One service member said, "we don't care if things go properly. We just don't want to get in trouble". That person and all others who participated in the study were granted confidentiality by RAND in order to speak freely.



The 13 launch officers who volunteered for the study scored an average of 4.4 on the burnout scale, tied for highest in the group. A group of 20 junior enlisted airmen assigned to missile security forces also scored 4.4.



This has always been considered hard duty, in part due to the enormous responsibility of safely operating nuclear missiles, the most destructive weapons ever invented.



In its Cold War heyday, an ICBM force twice as big as today's was designed to deter the nuclear Armageddon that at times seemed all-too-possible amid a standoff with the former Soviet Union and a relentless race to build more bombs.



Today the nuclear threat is no longer prominent among America's security challenges. The arsenal has shrunk - in size and stature. The Air Force struggles to demonstrate the relevance of its ageing ICBMs in a world worried more about terrorism and cyberwar and accustomed to 21st century weapons such as drones.



This new reality is not lost on the young men and women who in most cases were "volunteered" for ICBM jobs.



Andrew Neal, 28, who completed a four-year tour in September with FE Warren's 90th Missile Wing in Wyoming, where he served as a Minuteman 3 launch officer, said he saw marked swings in morale.



"Morale was low at times - very low," Neal said in an interview, though he added that his comrades worked hard.



Neal says his generation has a different view of nuclear weapons.



"We all acknowledge their importance, but at the same time we really don't think the mission is that critical," Neal said, adding that his peers see the threat of full-scale nuclear war as "simply non-existent." So "we practice for all-out nuclear war, but we know that isn't going to happen".



Every hour of every day, 90 launch officers are on duty in underground command posts that control Minuteman 3 missiles. Inside each buried capsule are two officers responsible for 10 missiles, each in a separate silo, armed with one or more nuclear warheads and ready for launch within minutes



They await a presidential launch order that has never arrived in the more than 50-year history of American ICBMs. The duty can be tiresome, with long hours, limited opportunities for career advancement and the constraints of life in remote areas of the north-central US.