Robert Peters, the former chief of strategic trends and effects for the Defense Threat Reduction Agency (DTRA) from 2019 to 2022, argues that some of the future Northrop Grumman [NOC] LGM-35A Sentinel ICBMs should field at bases but come with transporter erector launchers.
“Making a comparatively modest investment (an additional cost of roughly $20 billion over the next 50 years) in a slightly more diversified strategic arsenal will be well worth the money,” Peters, a research fellow for nuclear deterrence and missile defense at the Heritage’ Foundations Allison Center for National Security, wrote in a Jan. 11 study, It Is Time to Make the Next Generation of America’s ICBMs Road-Mobile.
“By putting a Sentinel on a vertical erector launcher attached to a truck, with security details on accompanying vehicles, it becomes a road-mobile ICBM—something that is, while not impossible, exceedingly difficult to target,” Peters wrote. “In this scenario, road-mobile Sentinels would be permanently stationed in garrisons on existing missile bases but could exit those garrisons and move around during exercises or times of crisis as a signaling tool. Air Force missileers could operate and drive them about on designated public and Defense Department roads and highways. By moving at a consistent speed along pre-approved (but not pre-planned) routes, road-mobile ICBMs could prove a near impossibility for adversaries to target, as the ICBMs would travel a few hundred miles every day.”
Such mobile ICBM concepts are not a novelty in the U.S. For example, the U.S. Air Force contracted with then Martin Marietta, now Lockheed Martin [LMT], to develop the MGM-134 “Midgetman” Small ICBM in the 1980s to counter a possible Soviet nuclear first strike, but the Pentagon canceled the program in 1992 upon the fall of the Soviet Union.
General Dynamics Electric Boat [GD] and HII [HII] are building the Columbia-class ballistic missile submarines (SSBN) to replace the 14 Ohio-class SSBNs, commissioned between 1984 and 1997.
The U.S. Navy said this week that HII had delivered the stern of the first Columbia-class boat, the USS District of Columbia (SSBN-826), to Electric Boat (Defense Daily, Jan. 10).
The Navy has said that it expects Electric Boat to deliver SSBN-826 by the fall of 2027 for deployment in 2031.
In the new Heritage report, Peters wrote that mobile Sentinels would be a “hedge” by the U.S. against adversaries’ possible development of “future technologies” that could detect U.S. SSBNs.
If mobile Sentinels “were armed with up to three nuclear warheads, they could present the equivalent striking power of a submarine-launched ballistic missile,” Peters wrote. “Given that they would operate deep inside American territory in relatively unpopulated areas and move on pre-determined but randomized routes, it would be virtually impossible for adversaries to track, target, and destroy them in real time, given the necessary flight times for even very fast missiles to traverse from Russia or China to the center of the United States. Should a launch on the American homeland be detected, the ICBMs could move to any number of launch sites to await further orders (to include launch or alert orders).”
Peters’ report references another, China’s Emergence as a Second Nuclear Peer: Implications for U.S. Nuclear Deterrence Strategy, in the spring of last year by Lawrence Livermore National Laboratory’s Center for Global Security Research (CGSR), which favors “seriously” considering mobile, garrisoned Sentinels, given what CGSR says is the dual nuclear threat posed by Russia and China.
In contrast to the Biden administration’s Nuclear Posture Review, last October’s congressionally-mandated Strategic Posture Commission report favors a nuclear build up, including an examination of mobile Sentinels.
“There are always people who want more, and we have been debating the issue of mobile ICBMs many times,” Hans Kristensen, the director of the Federation of American Scientists’ nuclear information project, wrote in a Jan. 12 email.
“It was an issue back in the days of the MX ICBM and it was an issue again in the initial phases of the future GBSD (now Sentinel) ICBM analysis and decisions,” he wrote. “Each time the idea of a mobile ICBM force has been rejected as impractical, too expensive, and not essential. People generally don’t like nuclear missiles driving through their neighborhood. Moreover, the greatest point of risk and vulnerability to nuclear weapons is during transport. And a mobile system would be a lot more expensive, not just because of the different infrastructure that would be needed to support it but also because it would require upgrades to roads and bridges in the areas the launchers would operate.”
“Although mobile launchers are normally thought to be less vulnerable to attack, that’s not necessarily the case,” Peters wrote. “On the ground, they are very vulnerable indeed. All it takes is a flat tire or a hand grenade to put it out of commission. We can see that concern clearly when Russia and China deploy their mobile ICBMs on exercises and spend a lot of resources and time protecting those launchers. Moreover, tracking mobile systems is getting easier because of improvements in satellite capabilities.”
In addition, Peters said that mobile Sentinels would not benefit deterrence.
“Part of the argument for mobile ICBMs is also the claim that the oceans might become transparent to new technology and the missile submarines, therefore, would become vulnerable to attack,” he wrote. “Although technology is improving, there is no indication that the subs would therefore lose their ability to hide in the foreseeable future. If that were the case, the United States should not start production of a new class of missile submarines, but this is where I find the argument for a mobile ICBM inconsistent: When you ask [U.S. mobile ICBM] advocates if the United States should cancel the Sentinel because fixed silos are vulnerable, they say no, and when you ask them if the United States should cancel the new missile submarine because they will become vulnerable to attack, they say no. So why is the mobile ICBM needed?”