弗吉尼亞核潛艇可能要變駝背了。

受預算削減影響最少的戰略核潛艇，美國很可能在現有弗吉尼亞攻擊核潛艇加一截26米的新垂直發射導彈艙段，同時能發射常規和核彈頭的洲際導彈，由於這新的中間26米身段比較高（美國弗吉尼亞攻擊核潛艇是10米，洲際導彈核潛艇俄亥俄是13），弗吉尼亞核潛艇可能要變駝背了。

By Elaine M. Grossman

The U.S. nuclear arsenal might be subject to cutbacks by a major budget review under way at the Defense Department, despite enjoying relative protection this year from largely across-the-board sequester spending reductions, a senior Defense official said on Thursday.

"Every part of the program, including nuclear weapons, is being addressed," the official said in an interview, referring to the ongoing Strategic Choices and Management Review led by Deputy Defense Secretary Ashton Carter.

The budget scrub is to advise Chuck Hagel, the defense secretary, by late this month on how best to apportion $500 billion in congressionally mandated funding reductions over the next decade. If President Obama can convince lawmakers to repeal the 2011 Budget Control Act, lesser but still-substantial cuts would likely be taken in 2014 and beyond.

The senior official -- who requested anonymity in this article to address politically and diplomatically sensitive topics -- appeared to suggest, though, that the Pentagon intends to keep ballistic missile-armed submarines relatively safe from the cost-cutting ax.

The big-ticket item coming down the pike for modernizing the Navy's aging "boomer" submarines and their Trident D-5 ballistic missiles is the estimated $90 billion Ohio-class replacement vessel, also dubbed "SSBN(X)."

"For SSBN(X), I don't see viable alternatives to going forward with the program," said the Defense leader, noting the Pentagon had already "made some significant adjustments" to program costs by delaying fielding of the first vessel by two years to 2031. "It's the most important element -- it's the central element -- of our triad."

That could leave the other two legs of the nuclear delivery arsenal -- Air Force bomber aircraft and ICBMs -- on the hot seat for reductions.

The service intends to field 80 to 100 new, conventionally armed Long-Range Strike bombers after 2020 that would later be certified for delivering nuclear weapons – though some pundits wonder if the new aircraft might remain conventional-only forever.

The Air Force insists that the bomber must be made dual-capable to help retain flexibility and redundancy in U.S. atomic forces. However, service Secretary Michael Donley acknowledged early this year that sequestration could endanger the timing or details of plans for the new airplane.

After 2030, the Air Force also plans to field a new Ground-Based Strategic Deterrent to replace today's 450 Minuteman 3 ICBMs. Here, too, the Pentagon is eyeing the potential for cutbacks, in the form of a life-extended or upgraded version of the Minuteman 3 rather than a new-design ballistic missile.

For both the ICBM and bomber legs of the triad, "we're looking at how do we sustain that capability and how do we do it at a reasonable cost, including both the delivery systems and the associated warheads and bombs," the senior Defense official told Global Security Newswire.

Speaking at a press conference on Friday, Donley said plans for the future ICBM could be at greater risk than for the next-generation bomber aircraft.

"I think [the spending review] has a little bit more effect on the ICBM side of the force structure, because on the bomber side we already know that we're going ahead with the Long-Range Strike," he told reporters. By contrast, the service is just beginning to weigh how it might replace the Minuteman 3.

Some defense analysts also see the Navy preparing its own "Plan B" for modernizing the nuclear-armed submarines.

The service is developing new strike capacity for its Virginia-class fast attack submarines that could allow the boats to launch ballistic missiles. To date the focus appears to be solely on adding conventionally armed weapons to the submersibles.

However, the "Virginia Payload Module" proposals to modify the current submarine design with a nearly 94-foot center section for ballistic-missile launch tubes appear strikingly similar to an alternative the Navy earlier dismissed for replacing the nuclear-armed Ohio-class submarines.

Some analysts argue the Navy should transition its atomic missiles to a smaller vessel such as the attack submarines at a time when traditional Cold War nuclear threats are receding. The Navy, though, said several years ago that the "humpback" center compartment required for the Virginia-class submarines to carry Trident ballistic missiles would reduce the vessels' speed, maneuverability and stealth.

No total program cost has been estimated for the proposed Virginia modification, but Navy budget documents show a price tag of nearly $800 million between 2013 and 2018 alone.

In terms of the size of the nuclear force, some Republicans on Capitol Hill have warned Obama against taking unilateral reductions below levels agreed by the Washington and Moscow in the New START accord, which allows each side 1,550 fielded strategic warheads and 700 fielded delivery vehicles.

They have also threatened to block implementation of the 2011 treaty if the administration does not make good on plans to modernize today's nuclear warheads and delivery systems.

The senior Defense official this week said the Pentagon's budget review -- nicknamed the "Skimmer" in keeping with its acronym -- would not itself address the policy option of nuclear reductions below New START levels.

However, the new assessment is being carried out in the "context" of "existing and pending policy guidance," the official said in the Pentagon interview.

"Pending" policy guidance would include a document currently sitting at the Oval Office for approval: The so-called "NPR Implementation Study," which is believed to recommend changes to nuclear doctrine and targeting that could form the basis for a smaller nuclear arsenal numbering 1,100 or fewer warheads.

"The conclusions are with the president," the senior official said of the implementing study, which was based on findings published in the Pentagon-led 2010 Nuclear Posture Review. "And when he says he has no more questions, and he signs, then we're done."

Donley said Obama will make a significant determination in summer 2014 regarding exactly how the New START reductions will be taken.

"The department and the nation's way forward on this still is dependent on some national-level decisions that the president plans, as I understand, to make next year," he said at the press briefing.

The bomber, said the outgoing Air Force secretary, "is really independent, in some respects, from the nuclear decisions that are still pending," because it also has a crucial conventional-attack role.

Meanwhile, plans for a new-design replacement for nuclear-armed submarines appear here to stay.

"As we look at the budgetary and fiscal environment that we're going to have for the next decade-plus, the department's going to have to make hard choices," the senior Defense official said on Thursday. "Sustaining a safe, secure and effective nuclear deterrent is a critical mission. Sustaining the sea-based element … with the follow-on to Ohio-class is critical for that."

The official acknowledged there is "still a significant cost" to plans for developing and buying 12 SSBN(X) vessels, despite the planned two-year delay in introducing them into the fleet.

Can the nation afford to build ballistic missile capability into two different families of submarines -- the Virginia class and the Ohio-class replacement -- during a time of fiscal austerity?

The senior official sounded slightly less committed when it came to the possible introduction of big conventionally tipped missiles for the Virginia attack submarines.

"Preserving our capability as a nation to undertake non-nuclear strikes is also critically important, both for operational capabilities and indeed as we think about our strategy over time to sustain advantage" over possible adversaries, the official said. "Sustaining, if not increasing, our non-nuclear strike capacity even in a time of budgetary austerity is something that the Department needs to at least tee up … for this and future secretaries."

Donley said the ongoing review could result in dusting off some previously jettisoned defense procurement alternatives in the interest of curbing spending.

"There are ways to address different aspects of the nuclear enterprise and how to modernize it and how much and on what schedule," he said on Friday. "We have lots of options for that. There are many programs involved."

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