Arguments For And Against Submarine Launched Nuclear Cruise Missiles

Nuclear armed cruise missiles are primarily designed to destroy aircraft carrier and other very large surface warships, and to destroy fortified bunkers, with a relatively small and agile weapon that is less vulnerable to missile defense systems than a ballistic missile that isn't very maneuverable. 

The U.S. military recently cancelled plans to develop a nuclear armed sea-launched cruise missile,  mostly because small nuclear warhead submarine launched ballistic missiles and aircraft launched nuclear cruise missiles are already available. A senior U.S. Navy reserve officer, meanwhile, argues that this was a bad call, because he doesn't trust aircraft to be reliable and because it would allow attack submarines to carry nuclear weapons, rather than leaving this is a much smaller fleet of ballistic missile submarines.

Lurking behind this debate is one that I have pressed for a long time, the argument that aircraft are usually better suited to destroying or disabling enemy warships than other warships. Aircraft have numerous advantages over surface warships which is comparable to going into a battlefield on ground in an RV.

Arguments that the Navy should deploy a nuclear-armed sea-launched cruise missile (SLCM-N)—particularly arguments centered on low-yield characteristics—contribute important points to ongoing discourse about U.S. nuclear modernization. But there is more to consider than yield. Senior policy-makers need to understand SLCM-N in the context of a broader question: How should the United States bolster theater deterrence distinct from but reinforced by strategic deterrence?

While yield matters, focusing on it diminishes other considerations and plays into established opposition. Recall that the 2022 Nuclear Posture Review (NPR) canceled SLCM-N in part because “the W76-2 low yield submarine-launched ballistic missile warhead, globally deployable bombers, dual-capable fighter aircraft, and air-launched cruise missiles” were considered sufficient for theater deterrence.

There are three stronger arguments for SLCM-N than firepower per se. First, it improves theater deterrence options by decreasing reliance on aircraft-delivered weapons. Second, it could complement or replace the W76-2, distributing some of the theater deterrence role to attack submarines (SSNs) while reserving ballistic-missile submarines (SSBNs) for higher levels of conflict. Third, SLCM-N contributes to U.S. arms control, assurance, and nonproliferation objectives as complementary facets of U.S. nuclear strategy.

From here.