While the Biden administration’s Nuclear Posture Review (NPR) has proposed retiring the B83 megaton capable gravity bomb, the Pentagon is to examine nuclear and conventional options against hard and deeply buried targets (HDBT).

The B83 has had “a dimishment of usefulness,” and the NPR “does point out that we need to do more work to make sure we can get after some of the hard and deeply buried targets–the so called HDBT,” Richard Johnson, the deputy assistant secretary of defense for nuclear and countering weapons of mass destruction policy, told an Atlantic Council forum on Nov. 1.

“We recognize that we’re going to have to get after those potential [HDBT] challenges with certain adversaries, and we’re going to be doing a major study lookong at what capabilities we could bring to bear to that challenge, whether those are nuclear or non-nuclear,” Johnson said.

Conventional munitions against such targets have included the Boeing [BA] AGM-157 Massive Ordnance Pentrator –a 20 foot, 30,000-pound bomb carried by U.S. Air Force B-2 stealth bombers by Northrop Grumman [NOC].

While the Biden administration has proposed retiring the B83 in fiscal 2023, Congress has rejected that idea in draft legislation (Defense Daily, Oct. 27).

The new NPR cancels the Trump administration’s proposed nuclear-armed Sea-Launched Cruise Missile (SLCM-N), but proposes retaining–at least for the short term–the Department of Energy National Nuclear Security Administration’s W76-2 low-yield nuclear warhead for ballistic missile submarines–another Trump adminstration initiative.

To deter Russian use of low-yield nuclear weapons, the NPR looks to the W76-2, the B61-12 bomb to be carried by the Lockheed Martin [LMT] F-35A and the Raytheon Technologies [RTX] AGM-181 Long-Range Standoff (LRSO) cruise missile for the U.S. Air Force. “To deter theater attacks and nuclear coercion of allies and partners, we will bolster the Triad with capabilities that further strengthen regional deterrence, such as F-35A dual-capable fighter aircraft (DCA) equipped with the B61-12 bomb; the W76-2 warhead; and the Long-Range Standoff (LRSO) weapon,” the NPR says.

The review said that the W76-2 “currently provides an important means to deter limited nuclear use” and that the W76-2’s “deterrence value will be re-evaluated as the F-35A and LRSO are fielded, and in light of the security environment and plausible deterrence scenarios we could face in the future.”