The U.S. will have the option of responding with nuclear weapons to a devastating non-nuclear attack -- an attack from biological or chemical weapons, for example -- officials said Friday in releasing the new Nuclear Posture Review (NPR).
The NPR also projected development of new low-yield warheads for ballistic missiles on submarines and a new sub-launched nuclear cruise missile, and included "tailored" strategies to deter North Korea, Russia, China and Iran.
In addition, the NPR stated that the U.S. had no intention of resuming nuclear testing to enhance the arsenal, "unless we find it necessary."
At a Pentagon briefing, DoD, Energy Department and State Department officials declined to give cost estimates on the NPR's proposals for modernizing the nation's nuclear triad of land-based missiles, long-range bombers and submarines, but the Congressional Budget Office has put the price tag at $1.2 trillion through 2040.
The goal of the NPR was to "keep America safe in this century with a deterrent that is modern and credible," and also to "give our diplomats leverage so they always speak from a position of strength," Deputy Defense Secretary Patrick Shanahan said at the briefing.
The nation's nuclear arsenal and triad had kept the U.S. safe 70 years for nuclear attack, and "We cannot afford to let it become obsolete," Shanahan said.
Since the development of nuclear weapons, the U.S. has never completely ruled out a first strike, but the NPR appeared to expand the circumstances in which a "first use" would be contemplated.
The NPR, which was overseen by Defense Secretary Jim Mattis, stated that the United States would only consider the use of nuclear weapons in extreme circumstances to defend the vital interests of the United States, its allies and partners.
However, Shanahan said that the NPR also "clarifies" the long-standing policy to state that "extreme circumstances" could include "significant non-nuclear strategic attacks" that would bring about a U.S. nuclear response.
Shanahan maintained that "this clarification is stabilizing" and would "lower the risk of nuclear use by anyone." He said "the United States does not want to use nuclear weapons," but "we do want to maintain an effective deterrent to keep Americans and our allies and partners safe and secure."
At the briefing, DoD Undersecretary for Policy John Rood declined to speculate on "hypotheticals" on when the U.S. would use nuclear weapons against a non-nuclear attack, such as a massive cyber attack that knocked out the power grid.
He said it was also long-standing U.S. policy to "maintain some ambiguity" on when the U.S. would use nuclear weapons. Root also said there was no "automaticity" to what the U.S. would do in undefined "extreme circumstances."
The 74-page NPR summary that was released Friday called North Korea a "clear and grave threat," and stated that any attack by the Kim Jong-un regime against the U.S. or its allies will bring about "the end of that regime."
"There is no scenario in which the Kim regime could employ nuclear weapons and survive," the NPR said.
State Department official Anita Fried said at the briefing that "I would not call this a Russia-centric NPR," but the summary underlined the need to convince Russia that it would face "unacceptably dire costs" if it were to threaten a limited nuclear attack in Europe against NATO allies.
Fried said that both Russia and China were given advance copies of the NPR to make clear U.S. policy and avoid the "risk of miscalculation."
In making the case for modernizing the triad, the NPR stated that the U.S. for decades led efforts at eat nuclear arms reduction worldwide and the efforts accelerated with the fall of the Soviet Union.
However, Russia in recent years has modernized its nuclear force and "even more troubling has been Russia's adoption of military strategies and capabilities that rely on nuclear escalation for their success," the NPR stated.
"China, too, is modernizing and expanding its already considerable nuclear forces," the NPR said. "Like Russia, China is pursuing entirely new nuclear capabilities tailored to achieve particular national security objectives while also modernizing its conventional military, challenging traditional U.S. military superiority in the Western Pacific."
In addition, "Iran's nuclear ambitions remain an unresolved concern," and "globally, nuclear terrorism remains a real danger," the NPR said.
"Our goal is to convince adversaries they have nothing to gain and everything to lose from the use of nuclear weapons," the NPR said and "in no way does this approach lower the nuclear threshold."
"Rather, by convincing adversaries that even limited use of nuclear weapons will be more costly than they can tolerate, it in fact raises that threshold," the NPR said.
"We must look reality in the eye and see the world as it is, not as we wish it to be," the NPR said, "given the range of potential adversaries, their capabilities and strategic objectives."
"This review calls for the diverse set of nuclear capabilities that provides an American President flexibility to tailor the approach to deterring one or more potential adversaries in different circumstances," the NPR said.
The last NPR was issued in 2010, and President Donald Trump ordered up the new one a week after he took office in January 2017.
In a statement Friday afternoon, Trump said that the conclusions of the NPR "are grounded in a realistic assessment of the global security environment, the need to deter the use of the most destructive weapons on earth, and our nation's long-standing commitment to nuclear non-proliferation."
Other nations have enhanced their stockpiles and capabilities, but previous U.S. administrations "deferred much-needed modernization of our nuclear weapons, infrastructure, and delivery systems," Trump said.
The new NPR provided a blueprint for modernizing and rebuilding the U.S. nuclear force, Trump said.
Under the NPR, the U.S. would pursue "modernization of our nuclear command, control, and communications, all three legs of our triad, our dual capable aircraft, and our nuclear infrastructure," Trump said.
-- Richard Sisk can be reached at Richard.Sisk@Military.com.