Summary and Key Points: The U.S. Air Force's Sentinel Program, aimed at modernizing its silo-based intercontinental ballistic missiles (ICBMs), faces rising costs and delays, prompting debate over its continuation. The new cost for the missile will reach $140 Billion. 

-Initially conceived in 2016 to replace the aging Minuteman III missiles, the program has encountered significant cost overruns and extended timelines.

-Critics question the wisdom of persisting with the program, given its escalating expenses and potential further delays.

Proponents argue that updating the nuclear arsenal is crucial, especially in light of increasing missile capabilities from nations like China. The decision hinges on balancing the program's costs with its strategic benefits in maintaining a robust nuclear deterrent.

Should the Sentinel ICBM Program continue?

The Sentinel Program is the U.S. Air Force’s effort to upgrade and modernize its inventory of silo-based intercontinental ballistic missiles. These nuclear-tipped weapons form the land leg of the U.S. nuclear triad. 

Recent reporting suggests the Sentinel program will be far more expensive than originally estimated and take longer to reach initial operating capability. The reports raise questions about the wisdom of continuing to develop these missiles. 

What is the Sentinel Program?

Conceived in 2016, the acquisition was initially called the Ground Based Strategic Deterrent and was the result of lobbying by lawmakers from states that house strategic nuclear missiles. The goal is to replace aging Minuteman III missiles currently armed in silos in Montana, North Dakota, and Wyoming. Those weapons systems have been in service for over 50 years and during that time have undergone multiple overhauls. The Air Force says no further upgrades are possible. The Department of Defense initially tabbed Boeing and Northrop Grumman to bid on a replacement. After Boeing’s withdrawal in 2019, Northrop Grumman was awarded the sole-source contract. 

Cost and Schedule Overruns

Several outlets have commented on the increased cost of the missiles. January cost projections ran so far outside of initial estimates that they incurred a critical Nunn-McCurdy breach, which prompted a review. In early July, Undersecretary of Defense for Acquisitions William LaPlante certified the program to continue in spite of the cost overruns. 

Most of the cost additions were found to be related to challenges upgrading the silo and the command and control infrastructure. This means implementing one of “the Air Force’s biggest civil works projects in recent times, and it is increasingly clear the service doesn’t know for sure how much time it will take or what it will cost.” 

Alongside questions about cost are questions about the timeline. The program was expected to reach initial operating capability by 2029. Now, however, best estimates don’t expect to see Sentinels in silos until the 2030s. 

Should It Continue?

In light of these challenges, detractors are beginning to wonder if the program will be worth it. While the Air Force is adamant it needs a new missile, it has managed to keep its venerable B-52 flying for longer than the Minutemen III has been in service.   

Furthermore, continuing the program could lead to more cost increases. The Government Accountability Office has already noted four further potential sources of overruns. 

Proponents point to the risks of staying the course or attempting to upgrade the current system. Due to silos’ vulnerability to attack, the Air Force is required to keep the crews on high alert to give them a chance to respond to an attack. Some fear that being in a constant state of readiness reduces the margin for error and increases the likelihood of nuclear war. Planners also point to China’s increase in missiles – there are currently more silos in China than in the U.S. – and to concerns that China’s forces may soon be able to detect U.S. ballistic missile subs with greater accuracy, negating an entire leg of the nuclear triad. 

Ultimately, nuclear strategists and Congress must work together to decide whether the costs of the program outweigh the benefits. The debate may even spill over into a discussion on the wisdom of silo-based weapons and their role in deterrence. However, it seems likely that for the moment at least, the Air Force will continue to develop the Sentinel.

About the Author: Maya Carlin 

Maya Carlin, National Security Writer with The National Interest, is an analyst with the Center for Security Policy and a former Anna Sobol Levy Fellow at IDC Herzliya in Israel. She has by-lines in many publications, including The National Interest, Jerusalem Post, and Times of Israel. You can follow her on Twitter: @MayaCarlin. 

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