WASHINGTON (WASHINGTON POST) - A leaked draft of the Pentagon's forthcoming nuclear weapons review shows that senior defence officials are keen to not only modernise the ageing US arsenal, but add new ways to wage nuclear war as Russia, China and other adversaries bolster their own arsenals.
Among the new weapons proposed are so-called "low-yield nukes" that could be mounted to existing Trident ballistic missiles launched from submarines.
Despite the nickname, the warheads would still likely pack a punch larger than the explosions that levelled the Japanese cities of Hiroshima and Nagasaki during World War II.
The draft, first published by the HuffPost, states that the smaller nuclear weapons are necessary due to the "deterioration of the strategic environment", a nod towards existing tensions with Russia, in particular.
The Pentagon's thesis: If an adversary has an arsenal of nuclear weapons that are not controlled by existing treaties, the United States should have one to match and retaliate if necessary.
"These supplements will enhance deterrence by denying potential adversaries any mistaken confidence that limited nuclear employment can provide a useful advantage over the United States and its allies," the draft said.
The concept seems especially focused on Russia, which the Pentagon accused of violating the New START Treaty last year by deploying a new nuclear cruise missile that is seen as a threat to Europe.
The Pentagon alleges in the draft that Russia thinks launching a limited nuclear strike first may offer an advantage, in part because it has a variety of small nuclear weapons at its disposal."Correcting this mistaken Russian perception is a strategic imperative," the draft said.
The Pentagon also calls for a new nuclear submarine-launched cruise missile, typically called a SLCM ("slick-em") in the military.
The Obama administration sought to phase out a similar cruise missile in a nuclear review it released in 2010, but defence officials now argue that it is necessary.
The new weapons could add additional costs to what already promised to be a very expensive Bill to modernise the nuclear arsenal, most of which is decades old.
An assessment by the Congressional Budget Office released last fall found that it will cost US$1.2 trillion (S$1.6 trillion) over the next 30 years to build new weapons and maintain them.
President Donald Trump directed Defense Secretary James Mattis early last year to launch the review to assess the state, flexibility and resiliency of the existing arsenal to deter modern adversaries.
In a statement on Friday, the Pentagon did not deny the draft document is legitimate but said it is Defence Department policy not to comment on "pre-decision" documents.
"Our discussion has been robust and several draft have been written," the statement said. "However, the Nuclear Posture Review has not been completed and will ultimately be reviewed and approved by the President and the Secretary of Defense."
The Pentagon is expected to release the nuclear review after Trump's State of the Union on Address on Jan 30, though it is not clear if the timeline has been altered by the draft's leakage. A variation of the review was carried out by each of the last two administrations, and typically informs strategy for years going forward.
Michaela Dodge, a defence analyst for the conservative Heritage Foundation, declined to comment on the document, citing its unauthorised leakage.
Broadly, however, she said some nuclear analysts have said adding new ways to deliver nuclear weapons could launch a new arms race.
"But my sense is that there already is a nuclear arms race," she said.
"It's just that the United States is not racing. It's actually standing by and observing while the Russians and the Chinese are building new nuclear capabilities, and the North Koreans are advancing their nuclear weapons capabilities and expanding them."
But others argue that the United States should not be building new weapons.
Jon Wolfsthal, a former Obama administration official who worked on nuclear issues on the National Security Council, said the Trump administration is on solid ground in sending a strong message that the United States will tolerate the use of nuclear weapons, but "runs off the rails" in arguing that new capabilities are needed.
Congress has rejected previous Pentagon efforts to add new submarine-launched warheads, in part because it isn't clear how Russia would react if a missile is launched at it and the size of the warhead on it could not be determined, Wolfsthal said.
"These are familiar debates for people in the nuclear community," Wolfsthal said.
"We've had them for many, many years, and some of them were considered and rejected under the Obama administration. Some of them were considered and pursued. But they now have the opportunity to push their agenda."