In June, Pentagon officials from the Strategic Systems Programs announced an $8 million order for technical engineering and integrated facilities acquisition and engineering pertaining to the development of the SLCM-N. 

Currently, the Trident II D5LE ballistic missiles, which can be equipped with nuclear warheads, make up the maritime component of the US military’s nuclear deterrent. Increased competition with China and Russia, however, is pushing the Pentagon to develop additional nuclear deterrence mechanisms to counter the long-standing nuclear capabilities of Russia and the emerging ones of China.

This would not be the first time the Navy has worked on a nuclear cruise missile. Back in the 1980s, the Navy developed a naval version of the BGM-109 Tomahawk Land Attack Missile (TLAM) that carried a nuclear warhead. The BGM-190 TLAM-Nuclear had a range of approximately 1,500 miles and could be fired from surface combatants and attack submarines. These munitions were not part of the arms control agreements between the United States and the Soviet Union.

However, in 1991, as part of the post-Cold War military drawdown, President George H.W. Bush announced the withdrawal of all land-based tactical nuclear weapons, as well as all sea-based tactical nuclear weapons from surface combatants, submarines, and naval aircraft. As a result, the Navy withdrew the TLAM-Nuclear missile and eliminated the nuclear mission from surface combatants. However, it kept the option to rearm missile-guided submarines with TLAM-Nuclear munitions in the future.

Key Issues

According to the Congressional Research Service, a main issue informing the development of the cruise missile system is its deterrence capability.

“A key issue in the SLCM-N debate is whether adding the missile to U.S. nuclear forces is necessary to credibly deter limited nuclear use by adversaries and assure allies in Europe and the Asia-Pacific that the United States would protect them from nuclear coercion,” the report states. 

In 2023, the Congressional Commission on the Strategic Posture stated that the US military needed a weapon system that could be forward deployed or deployable; be able to survive against preemptive attacks by near-peer adversaries; possess a range of explosive yield options, including low-yield capabilities; not require extensive force generation; and penetrate the air defenses of adversaries.

Although the commission did not specifically endorse the SLCM-N, its projected capabilities largely match those outlined by the bipartisan panel.

However, Navy submarines will need to receive the appropriate adjustments so that they can carry the SLCM-N, something that could delay the munition’s development.