Systemic problems in the Pentagon’s nuclear weapons programs will require a culture change and at least $7.5 billion in upgrades, top defense officials said Friday in announcing the results of two reviews prompted by a series of scandals earlier this year.

The changes are needed primarily in the Air Force’s nuclear missile force, although problems were also identified in the service’s bomber force and the Navy units that carry nuclear missiles on submarines. Combined, they form an aging nuclear “triad” that lost its former stature within the military after the end of the Cold War and as Washington shifted its focus and dollars to fighting wars in Iraq and Afghanistan.

Defense Secretary Chuck Hagel said “we just have kind of taken our eye off the ball here” in making sure that the military’s nuclear force is healthy.

“The good news is that none of this has endangered America, Americans, or put our security at risk. That’s all good news,” Hagel said. “But if we don’t pay attention to this, you know, if we don’t fix this, eventually it will get to a point where there will be some questions about our… security.”

Hagel called for the reviews in January after a scandal erupted at Malmstrom Air Force Base in Montana. Dozens of officers, who were entrusted with overseeing nuclear missiles kept in underground silos there, were implicated in a cheating scandal in which they shared answers to a routine launch proficiency test.

After internal and external reviews, Sec. of Defense Chuck Hagel announced Friday several changes to be made to the military's nuclear programs, for which he plans to request "billions of dollars of additional funding." (AP)

Shortly after Hagel called for the reviews, a similar scandal emerged at the Naval Nuclear Power School in Charleston, S.C. The service eventually expelled at least 34 senior enlisted sailors after finding that they had shared answers on an engineering watch qualification test.

An external review, carried out by retired Air Force Gen. Larry D. Welch and retired Navy Adm. John C. Harvey Jr., found that rank-and-file U.S. troops in the nuclear force are meeting the demands of their mission, but with increasing difficulty and are “paying an unsustainable price.”

The reviews, released Friday, found problems with manpower shortages, aging infrastructure, and an inspection system that created a culture of perfection, which troops couldn’t satisfy.

In total, the reviews recommended more than 100 changes. Some of them already have been implemented, officials said. The Pentagon will allow the Navy to hire 4,000 civilians to catch up on maintenance at its submarine shipyards, and the service has already begun hiring, Adm. Michelle J. Howard, the vice chief of naval operations, told reporters on Friday. The Air Force also will exempt 4,000 airmen working in the nuclear force from ongoing manpower reductions, and add nearly 1,00 military and civilian jobs to Global Strike Command, which oversees both bomber and missile wings.

Deputy Defense Secretary Robert Work said the Pentagon currently spends about $15 billion to $16 billion on nuclear programs each year, and will need to increase that by about 10 percent over each of the next five years to buy new helicopters for the troops who protect missile silos and make other improvements. Conservatively, that amounts to at least $7.5 billion in new spending.

The Pentagon also will upgrade Global Strike Command to have a four-star general oversee it. Currently it is commanded by Lt. Gen. Stephen Wilson, who took over in October 2013 and implemented an aggressive “Force Improvement Plan” this year to assess what went wrong. It is not clear if he will be nominated for the four-star job, said a command spokesman, Lt. Col. John Sheets.

In an unprecedented move, nine commanders in the missile force were removed from their jobs and a 10th resigned in March, following the cheating scandal. More recently, two additional commanders in the missile force were fired. One of them served at F.E. Warren Air Force Base in Wyoming; the other was at Minot Air Force Base in North Dakota.

Beginning Oct. 1, missile launch officers became eligible to receive up to $300 in incentive pay per month — an attempt by senior officials to underscore the importance of the mission. The Air Force also issued new uniforms, cold-weather gear and personal protective equipment to security force troops guarding the missile silos this year after they raised concerns about them during the review.