Defense Secretary Lloyd Austin's office on Monday certified the Sentinel nuclear missile program can continue after determining the effort is a major national security priority with no alternatives, despite its ballooning costs attracting increased scrutiny from Democrats on Capitol Hill.
The Office of the Secretary of Defense said it conducted a comprehensive and unbiased review of Sentinel after the program exceeded its cost projections by 37 percent in January, triggering a Nunn-McCurdy review that requires the Pentagon to consider whether to continue the program or axe it and to ensure it meets certain criteria to maintain funding.
The review found the program is vital to national security, has no alternative at a cheaper cost and is a higher priority than other programs that may be affected by continuing the funding for Sentinel. It also found the soaring costs to be reasonable and controllable if addressed.
But William LaPlante, the under secretary of Defense for acquisition and sustainment, rescinded the program's milestone B approval that allows it to enter the engineering and development phase, and he directed the Air Force to restructure Sentinel to understand the causes of the cost increases and to manage the effort more efficiently.
LaPlante said in a press release that his office is "fully aware of the costs" of Sentinel, which aims to replace the 400 Minuteman III intercontinental ballistic missiles (ICBMs) scattered across rural western parts of the country.
"But we are also aware of the risks of not modernizing our nuclear forces and not addressing the very real threats we confront," LaPlante said in the statement. "There are reasons for the cost growth, but there are no excuses. We are already working to address the root causes."
He added the Pentagon is "on the right path to defend our nation [while] protecting the sacred responsibility the American taxpayer has entrusted us with."
"The nuclear triad is the foundation of our national defense, and as our competitors modernize
their own nuclear forces, the urgency of pacing the threat is reflected in our Nuclear Posture
Review," LaPlante said.
The decision had been expected as the Air Force and other Pentagon officials had argued Sentinel should continue receiving funding. The fiscal 2025 budget request also includes funding for the program.
The Pentagon was slated to deliver its Nunn-McCurdy decision to Congress this week on the program. It comes just a little more than two weeks out from a July 24 hearing from Democrats on a congressional nuclear working group who has criticized the program.
A growing number of Democrats are expressing concerns about Sentinel, which is now projected to cost around $141 billion, up from $131 billion in January and around $60 billion when the program was getting off the ground around 2015.
A group of Democratic lawmakers sent a letter to Austin last month calling for an unbiased review of Sentinel and raising a number of concerns about the cost and effectiveness of the program.
Also on Monday, more than 700 scientists representing institutions across the country sent a letter to President Biden and Congress calling the U.S. to drop the Sentinel program from the budget. They argued it was "expensive, dangerous, and unnecessary."
Tara Drozdenko, director of the Global Security Program at the Union of Concerned Scientists, which organized the letter, said "there is no sound technical or strategic rationale for spending tens of billions of dollars building new nuclear weapons."
"These weapons — stored in silos across the Plains states — place a target on communities and increase the risk of nuclear war while offering no meaningful security benefits," Drozdenko said in a statement. "The U.S. could eliminate the land-based leg of the triad tomorrow and the U.S. public would only be safer for it."
Much of the cost increase for Sentinel is related to the real estate aspects of the program, since it involves not just creating brand-new missiles but also modernizing the infrastructure to support them.
The Pentagon said in the Monday press release that the review process determined the majority of the cost is in the command and launch segment, including the modernization of launch facilities and centers.
The restructuring of Sentinel will include addressing the command and launch segment, improving systems engineering and adjusting the contract structure and execution, according to Andrew Hunter, the assistant secretary of the Air Force for acquisition, technology and logistics.
"We do not take lightly the once-in-a-generation responsibility to modernize the ground leg of the nuclear triad, and are mindful of the scope and scale of this undertaking, which is unprecedented in contemporary times," Hunter told reporters in a press call. "Over the coming months, we'll develop a comprehensive plan for how the Air Force will restructure the program."
The Air Force will scale back the size and complexity of the launch facilities as part of the restructure plan. Officials will bring a new program baseline, which could vary in projected costs as being higher or lower than current estimates, to the Pentagon after restructuring Sentinel.
Still, Sentinel is expected to take funding from other programs. Gen. James Slife, vice chief of staff for the Air Force, told reporters Monday that in the future they may have to "decide what trade-offs we're going to need to make in order to be able to continue to pursue the Sentinel program."
Critics have questioned whether ICBMs are necessary, pointing to them as sitting targets that lack the perks of the other legs of the triad — submarines are stealthy, and bomber planes are fast.
But supporters have argued the U.S. must maintain and modernize all three legs of its triad to keep up with nuclear threats from Russia and China. The Minuteman missiles that Sentinel aims to replace are more than 50 years old.
Gen. David Allvin, chief of staff of the Air Force, said the U.S. faces "an evolving and complex security environment marked by two major nuclear powers that are strategic competitors and potential adversaries."
"While I have confidence in our legacy systems today, it is imperative that we modernize our nuclear triad," he said in a statement shared in the Monday press release. "A restructured Sentinel program is essential to ensure we remain best postured to address future threats."
The costs are eating into the program's schedule. Defense contractor Northrop Grumman, which won an initial roughly $13 billion contract for Sentinel in 2020 and is expected to continue work on the program, has already delayed its initial flight test by two years until 2026.
The Air Force wants to field Sentinel by 2030 but is likely to have to life-extend the Minuteman missiles amid the delays, something it has previously said it could not do. The Pentagon review on Monday determined that there will likely be a delay of several years.
