A Nuclear Sea-Launched Cruise Missile Sooner, Rather than Later
The MOC
By
Eli Glickman
June 11, 2024
“The current situation in Ukraine and China’s nuclear trajectory have further convinced me that a deterrence and assurance gap exists,” argued Admiral Charles Richard–then Commander of U.S. Strategic Command–in 2022 when he endorsed a nuclear sea-launched cruise missile capability (SLCM-N) as “necessary to enhance deterrence and assurance.”
After conducting its Nuclear Posture Review, the Biden Administration cut the SLCM-N. Congress, however, has continued to fund SLCM-N, and House Republicans led a push during the markup process for the 2024 National Defense Authorization Act to formally make SLCM-N a program of record.
The program, however, is likely to cost too much and come too late. Admiral Michael Gilday, then Chief of Naval Operations, estimated that the warheads for SLCM-N would cost $31 billion alone. Furthermore, when it was originally scrapped by the Biden Administration, senior Department of Defense officials estimated that, even if the program was fully funded, SLCM-N could not be delivered until 2035, much too late to deter Chinese nuclear escalation in a potential invasion of Taiwan that could occur before the end of the decade. Given the rigidity of defense procurement timelines, Congress should direct the Department of Defense to explore alternative capabilities to stand-in for SLCM-N in the near-term.
Luckily, the pieces are already there. As of 2022, the U.S. Navy had a stockpile of 4,000 Tomahawk Land Attack Missiles (TLAMs)—long range cruise missiles fired from surface ships and submarines. Open-source estimates indicate that the U.S. also has roughly 1,900 nuclear warheads kept in reserve. The United States could therefore constitute a SLCM-N capability by modifying a portion of these warheads to decrease their explosive yields and fitting them onto existing TLAMs. This is very likely to be technically feasible, as the Navy used to have nuclear-tipped TLAMs, which were retired in 2013.
A reconstituted nuclear-tipped TLAM would check all the boxes for deterrence and assurance that SLCM-N might check. Kyle Balzer of the American Enterprise Institute argued that SLCM-N, if deployed on nuclear-powered fast-attack submarines, would be deployable across the world, highly survivable, and be capable of penetrating China’s anti-access/area denial perimeter in the Indo-Pacific. A nuclear TLAM deployed on a fast-attack submarine would deliver the same capability. Moreover, a tactical nuclear weapon delivered by a cruise missile would be an inherently more credible deterrent than larger, ballistic-launched strategic nuclear weapons because it would be easier to use without inviting devastating retaliation. A TLAM is a suitable delivery platform for meeting these needs in the near-term, although a more advanced cruise missile might be necessary farther in the future.
Opponents of a SLCM-N contend that it would exacerbate escalation risks and could make nuclear weapons ‘more usable.’ This claim, counterintuitively, helps explain why tactical nuclear weapons are important tools. Simply put, a weapon that is more usable is a more credible deterrent because America’s adversaries would be more likely to believe the U.S. would actually use it. Brad Roberts, the director of the Center for Global Security Research at Lawrence Livermore National Laboratory, has argued that Chinese and Russian theories of victory consider nuclear weapons to be “instruments of coercion, blackmail, and brinksmanship” which could be used in a limited fashion to signal resolve and “persuade the United States and/or its allies to back down.” Given its credibility advantage, SLCM-N—or a nuclear-armed TLAM—would signal to China and Russia that neither country could gain an advantage from executing a coercive limited nuclear strike. A nuclear-tipped TLAM is therefore a credible deterrent and an effective near-term stand-in for SLCM-N.
Opponents also argue that deploying SLCM-N would reduce the availability of vertical launch tubes for conventional TLAMs on fast-attack submarines. That concern notwithstanding, Admiral Gilday expressed his confidence in the Navy’s ability to certify and deploy SLCM-N on its vessels. Moreover, it would be very difficult for U.S. adversaries to know whether a given Virginia-class submarine had nuclear TLAMs on it, so the Navy could deploy a relatively limited number while still achieving the desired deterrent effect. Indeed, despite the opportunity cost associated with conventional cruise missiles, General Mark Milley, the former Chairman of the Joint Chiefs of Staff, testified that he supported SLCM-N, as did Admiral Christopher Grady, the current Vice Chairman.
Congress should take the lead on investigating the utility of a nuclear-armed TLAM. Each year’s National Defense Authorization Act typically includes Committee Reports—prepared by the Senate and House Armed Services Committees, respectively—in which members of Congress can include directive items of special interest which direct defense officials to take certain actions. In this year’s Committee Reports, members of Congress should include items of special interest directing the relevant Department of Defense and National Nuclear Security Administration authorities to determine whether a nuclear-armed TLAM is technically feasible in the near-term and capable of filling existing deterrence requirements. Specifically, Congress should direct items of special interest on this matter to the Deputy Assistant Secretary of Defense for Nuclear Matters, the Commander of U.S. Strategic Command, the Under Secretary of Defense for Acquisition and Sustainment, the Secretary of the Navy, and the directors of each of the three Department of Energy weapons labs—Los Alamos, Lawrence Livermore, and Sandia.
Armed with information about the technical feasibility and military utility of a nuclear-tipped TLAM, Congress can move quickly to authorize and appropriate funds for the development, procurement, and deployment of this capability. Time is of the essence, and a nuclear-armed TLAM may be the United States’ optimal weapon for filling existing deterrence and assurance gaps.
Eli Glickman is a rising senior at the University of California, Berkeley, where he studies political science and public policy.
The views expressed in this piece are the sole opinions of the author and do not necessarily reflect those of the Center for Maritime Strategy or other institutions listed.
Center for Maritime Strategy
By Eli Glickman
“The current situation in Ukraine and China’s nuclear trajectory have further convinced me that a deterrence and assurance gap exists,” argued Admiral Charles Richard–then Commander of U.S. Strategic Command–in 2022 when he endorsed a nuclear sea-launched cruise missile capability (SLCM-N) as “necessary to enhance deterrence and assurance.”
After conducting its Nuclear Posture Review, the Biden Administration cut the SLCM-N. Congress, however, has continued to fund SLCM-N, and House Republicans led a push during the markup process for the 2024 National Defense Authorization Act to formally make SLCM-N a program of record.
The program, however, is likely to cost too much and come too late. Admiral Michael Gilday, then Chief of Naval Operations, estimated that the warheads for SLCM-N would cost $31 billion alone. Furthermore, when it was originally scrapped by the Biden Administration, senior Department of Defense officials estimated that, even if the program was fully funded, SLCM-N could not be delivered until 2035, much too late to deter Chinese nuclear escalation in a potential invasion of Taiwan that could occur before the end of the decade. Given the rigidity of defense procurement timelines, Congress should direct the Department of Defense to explore alternative capabilities to stand-in for SLCM-N in the near-term.
Luckily, the pieces are already there. As of 2022, the U.S. Navy had a stockpile of 4,000 Tomahawk Land Attack Missiles (TLAMs)—long range cruise missiles fired from surface ships and submarines. Open-source estimates indicate that the U.S. also has roughly 1,900 nuclear warheads kept in reserve. The United States could therefore constitute a SLCM-N capability by modifying a portion of these warheads to decrease their explosive yields and fitting them onto existing TLAMs. This is very likely to be technically feasible, as the Navy used to have nuclear-tipped TLAMs, which were retired in 2013.
A reconstituted nuclear-tipped TLAM would check all the boxes for deterrence and assurance that SLCM-N might check. Kyle Balzer of the American Enterprise Institute argued that SLCM-N, if deployed on nuclear-powered fast-attack submarines, would be deployable across the world, highly survivable, and be capable of penetrating China’s anti-access/area denial perimeter in the Indo-Pacific. A nuclear TLAM deployed on a fast-attack submarine would deliver the same capability. Moreover, a tactical nuclear weapon delivered by a cruise missile would be an inherently more credible deterrent than larger, ballistic-launched strategic nuclear weapons because it would be easier to use without inviting devastating retaliation. A TLAM is a suitable delivery platform for meeting these needs in the near-term, although a more advanced cruise missile might be necessary farther in the future.
Opponents of a SLCM-N contend that it would exacerbate escalation risks and could make nuclear weapons ‘more usable.’ This claim, counterintuitively, helps explain why tactical nuclear weapons are important tools. Simply put, a weapon that is more usable is a more credible deterrent because America’s adversaries would be more likely to believe the U.S. would actually use it. Brad Roberts, the director of the Center for Global Security Research at Lawrence Livermore National Laboratory, has argued that Chinese and Russian theories of victory consider nuclear weapons to be “instruments of coercion, blackmail, and brinksmanship” which could be used in a limited fashion to signal resolve and “persuade the United States and/or its allies to back down.” Given its credibility advantage, SLCM-N—or a nuclear-armed TLAM—would signal to China and Russia that neither country could gain an advantage from executing a coercive limited nuclear strike. A nuclear-tipped TLAM is therefore a credible deterrent and an effective near-term stand-in for SLCM-N.
Opponents also argue that deploying SLCM-N would reduce the availability of vertical launch tubes for conventional TLAMs on fast-attack submarines. That concern notwithstanding, Admiral Gilday expressed his confidence in the Navy’s ability to certify and deploy SLCM-N on its vessels. Moreover, it would be very difficult for U.S. adversaries to know whether a given Virginia-class submarine had nuclear TLAMs on it, so the Navy could deploy a relatively limited number while still achieving the desired deterrent effect. Indeed, despite the opportunity cost associated with conventional cruise missiles, General Mark Milley, the former Chairman of the Joint Chiefs of Staff, testified that he supported SLCM-N, as did Admiral Christopher Grady, the current Vice Chairman.
Congress should take the lead on investigating the utility of a nuclear-armed TLAM. Each year’s National Defense Authorization Act typically includes Committee Reports—prepared by the Senate and House Armed Services Committees, respectively—in which members of Congress can include directive items of special interest which direct defense officials to take certain actions. In this year’s Committee Reports, members of Congress should include items of special interest directing the relevant Department of Defense and National Nuclear Security Administration authorities to determine whether a nuclear-armed TLAM is technically feasible in the near-term and capable of filling existing deterrence requirements. Specifically, Congress should direct items of special interest on this matter to the Deputy Assistant Secretary of Defense for Nuclear Matters, the Commander of U.S. Strategic Command, the Under Secretary of Defense for Acquisition and Sustainment, the Secretary of the Navy, and the directors of each of the three Department of Energy weapons labs—Los Alamos, Lawrence Livermore, and Sandia.
Armed with information about the technical feasibility and military utility of a nuclear-tipped TLAM, Congress can move quickly to authorize and appropriate funds for the development, procurement, and deployment of this capability. Time is of the essence, and a nuclear-armed TLAM may be the United States’ optimal weapon for filling existing deterrence and assurance gaps.
Eli Glickman is a rising senior at the University of California, Berkeley, where he studies political science and public policy.
The views expressed in this piece are the sole opinions of the author and do not necessarily reflect those of the Center for Maritime Strategy or other institutions listed.