The Sentinel intercontinental ballistic missile (ICBM) nuclear weapons program, in which the Air Force is moving to replace its old land-based nuclear missiles with new ones, has been troubled from the start.
Running at more than 80% over-budget, the Sentinel’s gargantuan costs and slow development pace even triggered a critical DoD review under the Nunn-McCurdy Act, which says if a program exceeds a 25% cost overrun it must be terminated unless the Pentagon determines it meets the criteria to continue. The DoD insisted the Sentinel would continue.
Rather than consider all of this, the National Defense Authorization Act for fiscal year 2026, which authorizes the DoD’s budget and sets its priorities for the year, is poised to enable the Sentinel program’s gravy-train further. Indeed, House and Senate versions of the legislation, soon to be considered in Congress, would provide it with an additional $400 million and $2 billion in funding respectively.
Given the Sentinel’s track record, experts call the NDAA’s Sentinel funding push budgetary malpractice.
“It is an absolute disservice to American taxpayers for Congress to continue throwing funds in the money pit that they call the Sentinel program,” Mackenzie Knight-Boyle, a senior research associate at the Federation of American Scientists’ Nuclear Information Project, told RS.
“The Defense Department has failed to show it is even capable of executing this program,” she added, “with new ‘unforeseen’ challenges cropping up every couple of months and higher and higher cost estimates announced while the program fails to meet benchmarks.”
Efforts toward program oversight in the same legislative package, meanwhile, are flopping. An NDAA amendment by Rep. John Garamendi (D-Ca.), which would have restricted funds for the program until successfully completing Milestone B, failed in a 15-42 vote at the House Armed Services Committee markup preceding its consideration on the House floor.Challenging Sentinel
Broadly, proponents say a modernized ICBM program is key to maintaining America’s nuclear triad, a compilation of weapons systems and platforms which together aim to serve as a credible nuclear deterrent against adversarial attacks on American soil. They point out that the Minuteman ICBM, which has been in place decades longer than originally intended, is being phased out, thus needing to be replaced or refurbished.
But other experts increasingly take issue with ICBMs altogether, saying such weapons systems do little for national security while their placement on land invites, rather than deters, adversarial attack. And they assert that technological advances in other parts of the U.S. nuclear triad have proven adequate for nuclear deterrence, rendering the ICBM redundant. To this end, hundreds of scientists wrote to the Biden administration last year to request it retire the use of ICBMs as part of the U.S. nuclear arsenal entirely, calling ICBMs “expensive, dangerous, and unnecessary.”
William Hartung, a senior research fellow at the Quincy Institute’s Democratizing Foreign Policy Program, similarly told RS that ICBMs, of any kind, may escalate conflict in the event of an acute political crisis or attack.
ICBMs “pose serious security risks because a president would have only a few minutes to decide whether to launch them on warning of attack, increasing the risk of an accidental nuclear war triggered by a false alarm,” Hartung explained.
“There is no reason to rush the Sentinel when we should be debating about whether we should build it at all.”
Along this vein, other lawmakers are now challenging the Sentinel program existentially with new legislation, saying the funding sent to it is better used elsewhere.
Namely, senators Edward J. Markey (D-Mass.), Bernie Sanders (I-Vt.), Jeff Merkley (D-Ore.) and Chris Van Hollen (D-Md.) introduced the Investing in Children Before Missiles (ICBM) Act of 2025 on July 23, to pause funding for the Sentinel program, and redirect those funds to the U.S. Department of Education. Rep. Ro Khanna (D-Ca.) introduced companion legislation to pause development of the new Sentinel program in the house.
“Instead of sinking tens of billions of taxpayer dollars into propping up a relic of our outdated Cold War-era nuclear strategy — and raising the risk of global mass destruction — we can invest more in fostering greater opportunity for our next generation,” Sen. Van Hollen said of the senators’ new legislative push, citing the Sentinel program’s excessive costs and risks to national security. “If there ever was an opportunity for greater government efficiency, this is it.”
