WASHINGTON — The new head of U.S. Strategic Command, which oversees the country’s nuclear arsenal, is taking a less forceful tone on developing the sea-launched cruise missile than his predecessor, who was an unabashed champion of the program.

Gen. Anthony Cotton neither endorsed nor repudiated the sea-launched cruise missile nuclear program, commonly called SLCM-N, in a February letter to Congress. The letter — entered into the congressional record during Cotton’s testimony before the Senate Armed Services Committee last week — and the Biden administration’s proposed nuclear arsenal budget for fiscal 2024 lay the groundwork for another tussle with Congress over whether to proceed with SLCM-N.

“A low-yield, non-ballistic nuclear capability to deter, assure and respond without visible generation (similar to the characteristics of SLCM-N) offers additional options and supports an integrated deterrence approach,” Cotton wrote. “It is one of several possible nuclear or conventional capabilities the U.S. could develop to enhance strategic deterrence.

“I support funding to address the full range of possible options to address this challenge in a rapidly changing security environment with the backdrop of multiple adversaries.”

Congress authorized $25 million for continued SLCM-N research and development when it passed the FY23 National Defense Authorization Act in December. By contrast, the Biden administration’s FY24 budget request for the National Nuclear Security Administration does not include SLCM-N funding.

Proponents of SLCM-N in Congress heavily relied on Cotton’s predecessor, Adm. Charles Richard, to argue in favor of what they view as gaps in the United States’ low-yield, unobservable nuclear capabilities. In his own letter to Congress in June, Richard wrote that he supports SLCM-N despite the Biden administration’s attempts to cancel it, citing “the current situation in Ukraine and China’s nuclear trajectory.”

Richard retired when Cotton assumed leadership of Strategic Command in December.

“Cotton, who’s taking a more measured approach, is still open to it, but he’s not the adamant supporter that Richard was at all,” said Stephen Young, who lobbies for the Union of Concerned Scientists, a nuclear nonproliferation advocacy group. “He’s not wedded to that as the only possible way to fill that gap.”

Young noted that the W76-2 warhead equipped on submarine-launched ballistic missiles already provides the U.S. with a low-yield, unobservable capability — even if the country doesn’t have cruise missiles with those specific functions. Additionally, he argued that the U.S. is building the low-yield B61-12 gravity bomb that can launch from the new B-21 stealth bomber as a non-ballistic nuclear option.

“To me it’s a huge stretch to have to have all these things,” said Young, arguing that SLCM-N is “a nuclear warfighting tool that we don’t need” to achieve deterrence.

The proposed FY24 nuclear weapons budget also includes funding to maintain the B83 megaton gravity bomb, which is 80 to 100 times more powerful than the bomb dropped on Hiroshima, Japan, during World War II. The Biden administration wants to retire the B83, per its Nuclear Posture Review, but has yet to lay out a time frame to do so.

In the meantime, Congress used the FY23 defense authorization bill to prevent its retirement until the Pentagon identifies a replacement capability to strike hard and deeply buried targets.

“We are going to have to figure out how we are going to continue [with] what capabilities we have to go after [hard and deeply buried targets], whether conventional or nuclear,” Cotton told the Senate Armed Services Committee last week.

But Young argued that “there are very few scenarios where” the U.S. would want to strike hard and deeply buried targets using the B83 given the immense level of destruction that would ensue.

“If you want to hit the various facilities in North Korea and drop the larger bomb, you’ve got fallout — all of South Korea and Japan,” Young said.

Bryant Harris is the Congress reporter for Defense News. He has covered U.S. foreign policy, national security, international affairs and politics in Washington since 2014. He has also written for Foreign Policy, Al-Monitor, Al Jazeera English and IPS News.

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