An official website of the United States Government 
Here's how you know

Official websites use .gov

.gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS

A lock ( lock ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Sentinel Land-Based Nuclear Modernization Program Will Continue, With Changes

The Defense Department has announced its decision to continue to modernize the land-based leg of the nuclear triad with a program called Sentinel. That decision comes after the Air Force notified Congress in January that the program had exceeded its baseline cost and triggered what is known as a Nunn-McCurdy breach. 

The Nunn-McCurdy Amendment was enacted in 1983 as part of the 1982 Defense Authorization Act to curtail cost growth in the U.S. weapons procurement programs. 

A breach occurs when the program acquisition unit cost or average unit procurement cost within a program increases by 25% or more over the program's current acquisition baseline.

A missile flies though the air.
LGM-35A Sentinel
An illustration of the LGM-35A Sentinel is shown. The Sentinel is a program meant to replace the existing Minuteman III ground-based strategic deterrent.
Credit: Illustration courtesy of the U.S. Air Force
VIRIN: 220405-F-AF000-1309
 

When a breach occurs, a program must be terminated unless the undersecretary of defense for acquisition and sustainment certifies to Congress that the program meets established criteria to continue. 

During the media event, William A. LaPlante, the undersecretary of defense for acquisition and sustainment, said that during the past 120 days he has led a review to determine if the program meets the criteria to continue, and he has determined that it does. 

"Based on the results of the review, it is clear that a reasonably modified Sentinel program remains essential to U.S. national security and is the best option to meet the needs of our warfighters," LaPlante said. "As the milestone decision authority, today I am certifying that the Sentinel program meets the statutory criteria to continue."

There are five criteria established by Congress that a program must meet in order to continue following a Nunn-McCurdy breach. Those criteria include: 

  • Program continuation is essential to national security;
  • There are no alternatives to the program that will provide acceptable capability to meet the joint requirements at less cost;
  • The new estimates of the program acquisition unit cost or procurement unit cost have been determined by the director of Cost Assessment and Program Evaluation, or CAPE, to be reasonable;
  • The program is a higher priority than programs whose funding must be reduced to accommodate the growth in cost of the program; and
  • The management structure for the program is adequate to manage and control program acquisition unit cost or procurement unit cost. 

While LaPlante said the department would continue to pursue modernization of the land-based leg of the nuclear triad, he also said continuation of the program wouldn't be "business as usual." 

"The program will be restructured to address the root causes of the breach and ensure an appropriate management structure is in place to control costs," he said. "The total program acquisition costs for a reasonably modified program are estimated by the CAPE to be $140.9 billion, an increase of 81% compared to estimates at the program's previous Milestone B decision, in September of 2020." 

LaPlante said there are "reasons, but no excuses" for the cost growth, but also addressed the risk of not modernizing the land-based portion of the U.S. nuclear triad. 

"We fully appreciate the magnitude of the costs, but we also understand the risks of not modernizing our nuclear forces and of not addressing the very real threats we confront." 

Air Force Vice Chief of Staff Gen. Jim Slife addressed these threats and reinforced the role of the nuclear triad.

"Each leg brings unique complementary attributes which are mutually supporting and key to signaling and establishing deterrence amidst an increasingly complex and dynamic security environment which, for the first time, includes the People's Republic of China as a major nuclear armed power and strategic competitor," he said.  

As part of the decision to continue with the Sentinel program, LaPlante said he has rescinded the program's "Milestone B" decision. This is the decision made in the lifecycle of an acquisition program where it is authorized to enter the engineering and manufacturing development phase. 

He said he has also directed the Air Force to develop a plan to restructure the Sentinel program.  

"Preserving schedule will be a key consideration during this restructuring, but a delay of several years is currently estimated," he said. "It's important to note that Sentinel is truly a historic program to modernize the land leg of the nuclear triad. And its scale, scope and complexity are something we haven't attempted as a nation for over 60 years." 

Assistant Secretary of the Air Force for Acquisition, Technology and Logistics Andrew Hunter stated that over the coming months the Air Force will develop a comprehensive plan for how the program will be restructured.  

"Our goal is to ensure the long-term success and sustainability of the ICBM force as it continues to provide 24/7 strategic deterrence, standing ready to respond at a moment's notice as the most responsive leg of the nuclear triad," Hunter said. "We'll do what it takes to sustain Minuteman III to meet these warfighter requirements in the interim."

The U.S. has about 400 silo-based Minuteman III intercontinental ballistic missiles, also called ICBMs. The U.S. military has been developing replacements for its ground-based nuclear missiles through the Sentinel program. The Minuteman III has been in place since 1970 and has been life-extended several times. LaPlante affirmed, "Across the department, we are committed to ensuring we are on the right path to defend our nation while protecting the sacred responsibility the American taxpayer has entrusted us with."

Related Stories