The Pentagon’s Defense Science Board recently completed a study on how strategic nuclear forces will be used to blast deeply buried and hardened underground targets.

No details of the study were made public in an executive summary about the research on the board’s website, a sign that plans for strikes against the buried targets are secret.

Eric D. Evans, the board’s chairman, said the details were shared with senior Pentagon leaders. Contained in the undisclosed study are options to be used for “difficult target defeat” strikes or other missions for destroying deeply underground, hidden or hard-to-reach targets in a nuclear war, he stated. The goal is to assure U.S. military “operational dominance” in various wartime and crisis scenarios, he said.

Study participants considered recent intelligence on the threat and found additional intelligence is needed. Past studies and programs were also examined along with military “effects chain” options, and new systems architectures.

The study appears to be part of U.S. military strategic deterrence efforts against China’s large-scale nuclear military buildup and Russia’s exotic new nuclear arms.

China’s nuclear infrastructure — missiles, warheads and factories — has been built underground in hardened facilities spread out along a network of some 3,000 tunnels dubbed the “Great Underground Wall.” The sole nuclear penetrator in the U.S. arsenal is the B83 bomb, which the Biden administration tried to cancel.

Strategic nuclear force leaders told Congress the bomb is needed for holding at-risk underground targets in China, Russia and North Korea. All three nations have extensive hardened underground military facilities.

The B83 penetrated tens of feet into the ground before detonating, a feature designed, along with a floor-on bomb, to blast underground targets.

• Bill Gertz can be reached at bgertz@washingtontimes.com.