Reports and rampant speculation regarding Russia’s announcement of a new, high-threat nuclear cruise missile have many asking questions about the ultimate aims of the Pentagon’s recently released Nuclear Posture Review.

The Pentagon’s accelerated development of a “nuclear-armed” F-35 Joint Strike Fighter attack envelope, and other new nuclear weapons, is of critical importance to a new sweeping strategic nuclear weapons modernization and development strategy aimed at countering Russia, China, and North Korea — and addressing a much more serious global nuclear weapons threat environment.

Also read: No one wants Russia’s new fighter — they want the F-35

Adding a nuclear-capable F-35 to the air portion of the nuclear triad — to supplement the existing B-2, B-52, and emerging B-21 — will bring a new dimension to US nuclear attack options and place a new level of pressure upon potential adversaries.

Discussion of the F-35’s role in nuclear deterrence emerged recently during a House Armed Services Committee hearing on the Pentagon’s recently published Nuclear Posture Review.

In written testimony, Defense Secretary James Mattis cited the F-35 as an indispensable element of US and NATO nuclear deterrence.

“Modernizing our dual-capable fighter-bombers with next-generation F-35 fighter aircraft will maintain the strength of NATO’s deterrence posture and maintain our ability to forward deploy nuclear weapons, should the security situation demand it,” his testimony states.

Mattis also cited the emergence of the F-35 as a “nuclear delivery system” in the context of expressing grave concern that US nuclear weapons modernization has not, in recent years, kept pace with a fast-changing global threat environment.

“Nuclear delivery system development over the last eight years shows numerous advances by Russia, China, and North Korea versus the near absence of such activity by the United States, with competitors and adversaries’ developing 34 new systems as compared to only one for the U.S. —  the F-35 aircraft,” Mattis said in written statements.

Officials with the Office of the Secretary of Defense confirmed to Warrior Maven that Mattis here is indeed referring to an emerging “nuclear variant” of the F-35. Multiple news reports, such as Business Insider, cite senior officials saying a nuclear-armed F-35 is slated to emerge in the early 2020s, if not sooner. The F-35 is equipped to carry the B-61 nuclear bomb, according to a report in Air Force Magazine.

It makes sense that the F-35 would increasingly be called upon to function as a key element of US nuclear deterrence strategy; in recent months, F-35s deployed to the Pacific theater to participate in military exercises over the Korean Peninsula. The weapons, ISR technology, and multi-role functions of the F-35 potentially provide a wide range of attack options should that be necessary in the region.

Utilizing speed, maneuverability, and lower-altitude flight when compared to how a bomber, such as a B-2, would operate, a nuclear-capable F-35 presents new threats to a potential adversary. In a tactical sense, it seems that a high-speed F-35, fortified by long-range sensors and targeting technologies, might be well positioned to identify and destroy mobile weapons launchers or other vital, yet slightly smaller, on-the-move targets. As part of this equation, an F-35 might also be able to respond much more quickly, with low-yield nuclear weapons in the event that new intelligence information locating a new target emerges.

Related: Mattis wants the F-35 to be part of the US nuclear triad

The F-35 recently completed a series of weapons separation tests and is currently able to be armed with the AIM-9X, AIM-120, AIM-132, GBU-12, JDAM, JSOW, SDB-1 and the Paveway IV, Lockheed Martin data states. While it is not yet clear exactly how a nuclear weapon might integrate onto the platform, the F-35 is configured to carry more than 3500 pounds of ordnance in stealth mode and over 18-thousand pounds uncontested.

While senior Pentagon leaders are understandably hesitant to discuss particular contingencies or attack scenarios, the NPR is quite clear that a more pro-active nuclear weapons posture is aimed at strengthening “deterrence.”

After analyzing the global threat calculus, the NPR calls for rapid inclusion of two additional nuclear weapons options — to include a sea-launched, nuclear-armed cruise missile.

“A nuclear-armed, sea-launched cruise missile and the modification of a small number of existing submarine-launched ballistic missile warheads to provide a low-yield option – will enhance deterrence by ensuring no adversary under any circumstances can perceive an advantage through limited nuclear escalation or other strategic attack,” Gen. Paul Selva, Vice Chairman of the Joint Chiefs of Staff, told reporters.

Senior Pentagon leaders stress that neither of these new nuclear weapons recommendations in the NPR require developing new nuclear warheads or will result in increasing the size of the nuclear stockpile. NPR DoD advocates further stress that the addition of these weapons does align with US non-proliferation commitments.

Mattis and other senior leaders seem aware that elements of the NPRs strategic approach may reflect a particular irony or paradox; in response to questions from lawmakers about whether adding new low-yield nuclear weapons could “lower the threshold” to nuclear war and therefore introduce new elements of danger, Mattis told Congress that increasing offensive nuclear-weapons attack capability will have the opposite effect, meaning the added weapons would improve deterrence and therefore enhance prospects for peace.

Specifically, Mattis explained that a new, low-yield, submarine-launched ballistic missile could likely provide pressure on Russia to a point where they might be more inclined to negotiate about adhering to the INF treaty they have violated.

“We have an ongoing Russian violation of the INF. We want our negotiators to have something to negotiate with because we want Russia back in compliance,” Mattis told lawmakers.

Alongside this strategic emphasis, Mattis also stressed that the NPR stipulates that nuclear weapons will only be used in the most extreme cases, adding that the “use of any nuclear weapon is a strategic game changer. Nuclear deterrence must be considered carefully.”

Citing the rapid technological progress of adversary air-defense systems, Mattis further elaborated that a sea-launched cruise missile option might be necessary to hold potential enemies at risk in the event that air-dropped low-yield weapons were challenged to operate above necessary targets.

“To drop a gravity bomb that is low-yield means a bomber would have to penetrate air defenses. Air defenses are very different than they were 20 years ago,” Mattis told Congress.

For instance, Russian-built S-400s and an emerging S-500 are potentially able to detect aircraft at much further ranges on a larger number of frequencies. Furthermore, faster computer processing and digital networking enable dispersed air defenses to hand off targets quickly across wide swaths of terrain.

This phenomenon also provides indispensable elements to the argument in favor of the Pentagon’s current development of a new nuclear-armed, air launched cruise missile – the Long Range Stand-Off weapon (LRSO). In similar fashion, a nuclear cruise missile could hold enemy targets at risk in a high-tech threat environment where bombers were less able to operate.

Some critics of the LRSO maintain that the introduction of the LRSO brings a “destabilizing” effect to the possible use of nuclear weapons. In a manner quite consistent with the current NPR, senior Air Force weapons developers told Warrior Maven over the course of several interviews that, by strengthening deterrence, the addition of a new LRSO is expected to have the reverse – or “stabilizing” – effect by making it more difficult for a potential adversary to contemplate a first strike.

More reading: This is who will likely build America’s new nuclear missiles

NPR proponents say a strengthened and more wide-reaching nuclear weapons approach is necessary, given the current threat environment which does, without question, seem to be raising the possibility of nuclear confrontation to a level not seen in years.

“We’re concerned about: some of the adjustments in potential adversaries’ thinking about nuclear weapons. With a greater reliance on nuclear weapons, a featuring of them, in some cases — for example, in the Russian nuclear doctrine, called “Escalating to De-escalate.” John Rood, Undersecretary of Defense for Policy told reporters when discussing the NPR.

From the Nuclear Posture Review

Russia’s belief that limited nuclear first use, potentially including low-yield weapons, can provide such an advantage is based, in part, on Moscow’s perception that its greater number and variety of non-strategic nuclear systems provide a coercive advantage in crises and at lower levels of conflict. Recent Russian statements on this evolving nuclear weapons doctrine appear to lower the threshold for Moscow’s first-use of nuclear weapons.

The text of the report specifically cites the importance of dual-capable aircraft (DCA) in Europe and states that the F-35 is fundamental to deterring Russia.

“We are committed to upgrading DCA with the nuclear-capable F-35 aircraft. We will work with NATO to best ensure — and improve where needed — the readiness, survivability, and operational effectiveness of DCA based in Europe,” the Nuclear Posture Review states.

New ICBM

The NPR also seeks to accelerate ongoing efforts to modernize the air, sea and ground portions of the nuclear triad. DoD is immersed in current efforts to fast-track development and prototypes of a new ground-based strategic deterrent ICBM, Air Force developers have told Warrior Maven.

Early prototyping, including expected prototype “shoot off” testing is slated for 2020, service developers have told Warrior Maven in recent interviews. Northrop Grumman and Boeing are both now under contract to build the new weapon. The Air Force plans to build at least 400 GBSDs, Air Force senior leaders have said.

Critical elements of the new ICBM, developed to replace the decades-old Minuteman IIIs, will feature a new engineering method along with advanced command control, circuitry, and guidance systems, engineers have said.

New bomber

Regarding the air component, the Air Force recently completed a critical design review of its new B-21 Raider nuclear-capable stealth bomber. As is often the case with nuclear weapons, many of the details regarding the development of this platform are not available, but there is widespread discussion among US Air Force leaders that the bomber is expected to usher in a new era of stealth technology; much of the discussion focuses upon the bomber’s ability to operate above advanced enemy air defenses and “hold any target at risk anywhere in the world,” the Air Force Military Deputy for Acquisition Lt. Gen. Arnold Bunch has told Warrior Maven in past interviews.

Early available renderings of the bomber show what appears to be an advanced B-2 like design, yet possibly one with a lower heat signature and improved stealth properties. However, service leaders are quick to point out that, given advancements in Russian air defenses, stealth will surge forward as “one arrow in a quiver” of nuclear attack possibilities.

Concurrently, the Air Force is surging forward with a massive B-2 modernization overhaul, involving new digital nuclear weapons capability and the integration of a developing system called the Defensive Management System. This enables the B-2, which Air Force developers acknowledge may indeed be more vulnerable to advanced air defenses than in earlier years when it was first built, to more quickly recognize locations of enemy air defenses at safer ranges as a means to avoid detection.

New nuclear-armed ballistic missile submarine

Finally, shifting to a program widely regarded as among the most significant across the DoD enterprise, the Navy is already underway with early development of the new nuclear-armed Columbia-class ballistic missile submarines. Several key current efforts with this, including early “tube and hull” forging of missile tubes, work on a US-UK common missile compartment, and little-discussed upgrades to the Trident II D5 nuclear missiles.

Undersea strategic deterrence, as described by Navy and Pentagon leaders, offers a critical means to ensure a second strike ability in the event of a catastrophic first-strike nuclear attack impacting or disabling other elements of the triad.

Related: The F-35 could shoot down ballistic missiles — with one catch

While it may seem obvious, nuclear deterrence hinges upon a recognizable, yet vital contradiction; weapons of seemingly limitless destructive power are ultimately employed to “keep the peace” and save lives. Along these lines, Senior Navy and Air Force nuclear weapons developers routinely make the point that, since the advent of nuclear weapons, the world has managed to avoid massive, large-scale major power force on force warfare.

While Pentagon leaders rarely, if ever, offer a window into current nuclear-strike capabilities, it is widely discussed that the current North Korean nuclear threat is leading US military planners to envision the full spectrum of nuclear weapons contingencies. Even further, the US did recently send B-2 bombers to the Asian theater — stationing them in Guam.