The bill to modernize the nuclear Triad's three legs will be hefty, estimated at a total cost of over $300 billion in today's dollars. To ease this fiscal burden, the Navy is advocating a "smart" commonality approach, sharing designs and components between the Air Force Ground Based Strategic Deterrent (GBSD) and Navy's new submarine- launched ballistic missiles.  This proposal seeks to achieve modernization of the two missile legs of the Triad at a lower cost.  

This seems practical, considering the first of the Ohio-class nuclear submarines will be retired in 2027, the Minuteman intercontinental ballistic missile (ICBM) is nearly 50 years old and will need to be recapitalized by the early 2030s, and our B-52H bomber fleet will be 75 years old by the time the new B-21 bombers reach initial operating capability in the mid-2030s. But the logic is fraught with acquisition and operational risks. Historically, the promises of cost and time savings from commonality have proved elusive. Indeed, commonality-driven programs have often led to cost overruns, schedule slips, and cancellations — the exact outcomes the Department of Defense is seeking to avoid when time and money are running short.  A common design is predicated upon a common requirement across participating services.  But there are vast differences in operating environments between the Trident's deep blue sea and Minuteman's underground silos adjacent to mid-western cornfields. 

In fact, difficulty developing common requirements is a major reason why many joint programs either fail to materialize or stumble in execution.  Take for example the 1960s tactical-fighter experimental (TFX) initiative meant to introduce a common tactical fighter platform.  The difficulty of settling on a single one-size-fits-all set of requirements eventually forced the TFX to break up into several different aircraft programs, including the A-10, A-7, AV-8B, F-111, and F-14.  Similarly, the F-16 and F-18 were originally conceived as a single common light-weight fighter program before the services parted ways. Unfortunately, lessons encountered are not always lessons learned, and the F-35 program, pursuing a common fighter for the Navy, Air Force, and Marine Corps, has also been plagued by delays and cost overruns.

A good acquisition strategy seeks to lower costs and speed schedules.  To avoid systems failures, Minuteman III must be recapitalized in the early 2030s, leaving about 15 years to develop, test, and produce GBSD.  But if the Air Force and Navy pursue a common design—assessing the proposed design, re-evaluating requirements, and conducting trade-off analyses—the acquisition schedule will slip. However, as the Air Force is advancing to the technical maturation and risk reduction stage of GBSD, the Navy has not released any technical details to the Air Force,

Perhaps most troubling, however, is the fundamental risk this approach introduces to our nuclear posture.  A common missile design undermines the Triad by introducing interdependencies between two of the three legs.  For decades, the United States and Russia have maintained sea, air, and ground-based legs of their strategic nuclear forces to preserve an assured second strike capability.  The deadly logic is that an adversary will be deterred from launching a surprise nuclear attack if it believes that the other party has the ability to launch an equivalent retaliatory strike.  Key to preserving a second strike capability and strategic stability is maintaining three separate and independent legs of the Triad, ensuring that if one leg were compromised, the remaining legs would still stand ready.  Safeguarding that independence has in the past led the United States to rule out common missile designs between the ground and sea legs, thus preventing a single point of failure. 

In that light, a common design with identical components creating interdependencies between the missile legs of the Triad appears unwise. Stand-downs of entire fleets owing to defects or component failures are not uncommon.  Virtually every major aircraft weapons system has been grounded over the years, including the F-22, F-35, F-16, F-117, F/A-18 and B-1.  Should a common missile component fail on a new generation of long-range missiles, it would adversely impact approximately 75 percent of the US nuclear deterrent, forcing the US to rely entirely—even if just temporarily—on its limited bomber fleet.

Moreover, given all the trouble and risks endemic to common designs, this proposed approach saves relatively little—perhaps $600 million dollars in acquisition costs or less than 0.7 percent of the anticipated GBSD cost.  In effect, the Navy is asking the Air Force to gamble that absorbing new cost and schedule risks associated with commonality may result is some marginal program savings.  This is a far cry from savvy acquisition practice.

In sum, a common design for the new ICBMs and SLBMs would do little in the way of cost savings, but do much in spoiling the chances of delivering a timely, effective, and affordable replacement for the Minuteman III. A good acquisition strategy outfits the warfighter with needed capabilities at acceptable prices.  A smart acquisition strategy would achieve the same capability at lower than expected costs.  The commonality approach being advocated for the acquisition of a new generation of Air Force and Navy strategic missiles does neither.

By M. Thomas Davis, a former defense industry executive and a retired Army officer.  He is the author of numerous studies and articles on defense management policies.