The U.S. military is planning to add multiple nuclear warheads to aging Minuteman III intercontinental ballistic missiles to increase their deterrence firepower until the troubled Sentinel missile system can be deployed, Congress’ Government Accountability Office disclosed in a report made public Wednesday.
The 42-page GAO study is an unclassified version of an earlier secret report urging the Air Force to quickly resolve problems with transitioning from aging and hard-to-maintain Minuteman IIIs to new Sentinels.
The U.S. military can maintain nuclear deterrence of threats from China, Russia and North Korea during missile modernization, the report said. The U.S. Strategic Command told GAO the Air Force meets strategic deterrence requirements “day-to-day,” the report said.
However, the GAO said adding multiple independently targetable reentry vehicles, or MIRVs on Minuteman IIIs could “help mitigate risk of potential Sentinel delays during force transition.”
The Air Force Global Strike Command’s 2020 transition and deployment strategy included the option to re-MIRV all or some 400 Minuteman III ICBMs during the shift to Sentinels.
Current Minuteman IIIs have a single warhead, but can be outfitted with up to three warheads.
The added warheads would require a change in U.S. nuclear policy, the report said.
“Global Strike Command officials emphasized they would prefer as much lead time as possible to implement any potential re-MIRV decision due to the complexity of operations and additional logistical workload required to accomplish such a requested change,” the report said.
Additional details on the plan for re-MIRVing are classified, the report said.
The Pentagon’s 2022 Nuclear Posture Review said the United States retains the capability to upload warheads on its ICBMs but continues to favor single warheads to reduce “adversary incentive to launch a first strike,” the report said.
Both Chinese and Russian nuclear missiles include MIRVs. Some of China’s ICBMs are armed with three warheads and Russian ICBMs can be outfitted with up to 10.
One of the GAO’s six recommendations to the Air Force is for the service to “specifically address the personnel and materiel implications of a decision to re-MIRV ICBMs as part of the overall transition risk management plan.”
The plan to add warheads to Minuteman IIIs is part of a report that criticizes the Air Force for not developing a risk management plan for ICBM modernization that would “identify, assess, and respond to the myriad risks” of operating old and new ICBMs together until all old missiles are replaced.
The Air Force plan calls for deploying the first new ICBMs at F.E. Warren Air Force Base in Wyoming.
Also, the Air Force has failed to build a Sentinel test facility that is needed to train security forces charged with protecting the forthcoming missiles.
The report is the latest setback for the Pentagon’s strategic nuclear modernization program that is struggling to replace the single-warhead Minuteman III nuclear missiles in three fields in Wyoming, Montana and North Dakota. The missile was first deployed in 1970 and is 40 years past the date the missiles were expected to be replaced.
The Pentagon estimates deployment of replacement Sentinel missiles is delayed “by years,” the report said, with costs estimated to be around $140 billion.
In January, the Air Force notified Congress that the Sentinel breached a statutory cost threshold requiring a program review and potential cancellation.
Sentinel costs had increased by 37% and current estimates to total program costs are expected to be much higher, the report said.
In July, the Pentagon certified that the Sentinel program would continue and ordered the Air Force to restructure the program.
The increased costs were the result of what the Defense Department said was an unrealistic delivery schedule; ineffective engineering and incomplete basic system design and “an atrophied ICBM industrial base,” the report said.
Initial plans called for keeping all 400 Minuteman IIIs active until 2030 and retiring all by 2036.
Now, due to Sentinel delays, the Air Force is considering keeping the Minuteman III deployed until 2050, the report said.
“Sentinel delays mean the Air Force must operate the aging Minuteman III longer than planned — potentially significantly longer,” the report said, noting limited parts pose a risk to continued flight tests beyond 2030.
Other recommendations called for the Air Force to develop a plan to manage risks from the transition from Minuteman IIIs to Sentinels, and to build a test facility for Sentinel security forces.
Test launch plans and overall sustainment efforts for Minuteman IIIs after 2030 are also needed by the Air Force.
The GAO report on multiple warheads was disclosed following a report published in July by two U.S. strategic nuclear weapons experts that urged uploading MIRVs on Minuteman III as a short-term way to bolster flagging U.S. nuclear deterrence.
As China and Russia rapidly built up nuclear forces, the United States rapidly needs to add warheads to its missile forces, states the report, “Tailored Deterrence and Low-Cost Nuclear Weapons Upload,” by Mark B. Schneider, a former Pentagon nuclear strategist, and strategic weapons expert Keith B. Payne. Both are with the National Institute for Public Policy.
The report calls for adding multiple warheads to 400 land-based Minuteman III intercontinental ballistic missiles and to the Navy’s submarine-launched ballistic missiles.
“At this point, nuclear upload is likely the only way America can adequately enhance the force size and flexibility needed to tailor deterrence in the near term for the prevention of great power conflict, including major aggression against U.S. allies,” the report said.
Uploading warheads to existing missiles is “urgent” considering the threat of potential opportunistic or coordinated Russian, Chinese and North Korean aggression.
Trident submarine missile uploading would increase the current force from about 960 warheads to 1,626. Minuteman III uploading would bring the number of warheads from 400 to about 1,000.
“Additionally, there will be several hundred bomber weapons which could be somewhat increased via uploading,” the report said.
Costs of adding the warheads would be relatively modest and limited to transportation and warhead installation, estimated to be about $100 million over several years.
