A sea-launched cruise missile - nuclear (often abbreviated SLCM-N) is a cruise missile carrying a nuclear warhead that is launched from a naval platform, typically an attack submarine or surface combatant. Unlike submarine-launched ballistic missiles (SLBMs) carried on dedicated SSBNs, nuclear SLCMs can be dispersed across a wide fleet, complicating an adversary's targeting calculus and giving commanders a lower-yield, theater-range option distinct from strategic ballistic forces.
The concept has a Cold War lineage. The United States deployed the nuclear-armed Tomahawk (TLAM-N) aboard attack submarines and surface ships beginning in the mid-1980s. Under the 1991 Presidential Nuclear Initiatives announced by President George H. W. Bush, the warheads were removed from ships and placed in central storage; the Soviet Union under Mikhail Gorbachev reciprocated with parallel withdrawals of tactical naval nuclear weapons. The Obama administration's 2010 Nuclear Posture Review formally retired the TLAM-N.
Interest revived in the U.S. 2018 Nuclear Posture Review, which called for a new nuclear SLCM to counter perceived Russian non-strategic nuclear advantages and to provide an additional regional deterrent in Europe and the Indo-Pacific. The 2022 Nuclear Posture Review under the Biden administration recommended cancellation, but the U.S. Congress has repeatedly added funding for the SLCM-N program in subsequent National Defense Authorization Acts, keeping it alive as of recent budget cycles.
Debates around SLCM-N typically involve:
- Deterrence value vs. redundancy with air-launched and ballistic systems.
- Discrimination risk: an adversary detecting a launch cannot easily tell whether the missile is conventional or nuclear, raising escalation concerns.
- Naval opportunity cost: tubes and crew training devoted to nuclear missions reduce conventional strike capacity.
- Arms control implications: SLCMs are not captured by New START, which limits only strategic delivery vehicles.
Russia, France (historically), and reportedly other nuclear states have at various points fielded or studied analogous systems.
Example
In the FY2024 National Defense Authorization Act, the U.S. Congress provided funding for the SLCM-N program despite the Biden administration's 2022 Nuclear Posture Review recommending its cancellation.
Frequently asked questions
An SLBM is a long-range ballistic missile launched from a dedicated ballistic missile submarine (SSBN), while an SLCM-N is a lower-flying, slower cruise missile that can be fired from attack submarines or surface ships, generally with shorter range and smaller yield.
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