“It will take all of us working together – government officials, and diplomats, academic experts, and scientists, activists, and organizers – to come up with new and innovative approaches to strengthen transparency and predictability, reduce risk, and forge the next generation of arms control agreements.”
– Wendy Sherman
U.S. Deputy Secretary of State
June 2, 2022
Report Says U.S. Studying New Nuclear Capabilities

Philipp C. Bleek

A report to Congress on destroying hard and deeply buried targets (HDBTs) that was made public in late December does not explicitly call for new nuclear weapons development, as some analysts had expected, but clearly indicates that the Defense and Energy departments are actively studying developing new or modified nuclear weapon capabilities.

The fiscal year 2001 defense authorization act mandated the report, requiring the Energy and Defense departments to complete a study by July 1 “relating to the defeat of hardened and deeply buried targets.”

Submitted to Congress in October, the unclassified component of the report, dated July 2001, was made public by nongovernmental organizations. The report states that, although the United States currently has no programs to develop new or modified nuclear weapons to defeat hardened and deeply buried targets, the Defense Department (DOD) and Energy Department (DOE) are “investigating potential options and costs.”

The report lays out two possible justifications for developing new nuclear weapons capabilities. It says that, “with the current strategy and acquisition initiatives, the United States will not be able to hold all known or suspected HDBTs at risk for destruction, especially the deep underground facilities.” The report also notes, “Nuclear weapons have a unique ability to destroy both agent containers and [chemical and biological weapon] agents.”

The United States currently deploys at least one low-yield nuclear weapon designed to threaten hardened targets. The B61-11 tactical nuclear gravity bomb, first deployed in late 1996, can penetrate reinforced concrete or rock to a relatively shallow depth before detonating, thereby threatening bunkers and other hardened or deeply buried targets.

But the report faults the current nuclear weapons stockpile’s ability to deal with such targets. Although the stockpile possesses “some limited ground penetration capability and lower yield options,” it was not developed specifically to defeat hardened and deeply buried targets or destroy chemical and biological agents, the report says.

Both the Defense and Energy departments “have completed initial studies on how existing nuclear weapons can be modified to defeat those HDBTs that cannot be held at risk with conventional high-explosive weapons or current nuclear weapons,” the report says. But it notes that “comprehensive reviews of feasibility for suitable nuclear and conventional weapons…are still underway to support DOD and DOE budget decisions in the coming two years.”

The report also indicates that the Defense and Energy departments are already laying the groundwork for possible development of new or modified nuclear capabilities. “For destruction of more deeply buried facilities, DOD and DOE are studying the sensitivities and synergies of nuclear weapon yield, penetration, accuracy, and tactics.” The departments have formed a joint nuclear planning group “to define the appropriate scope and option selection criteria for a possible design feasibility and cost study.”

Congress would have to overturn a 1993 restriction on researching and developing low-yield nuclear weapons before the Pentagon could proceed with work on new nuclear weapons with yields under five kilotons. At a January 9 briefing on the administration’s recently completed nuclear posture review, Assistant Secretary of Defense for International Security Policy J. D. Crouch said that the posture review contains no recommendations about developing new nuclear weapons. However, he said that the United States is “trying to look at a number of initiatives,” including modifying an existing nuclear weapon to develop a “greater capability” against hard targets and deeply buried targets.