The U.S. Defense Department plans to develop a new conventional ballistic missile for fielding on attack submarines, according to major budget decisions announced on Thursday at the Pentagon (see GSN, Dec. 23, 2011).
“The Navy will invest in a design that will allow new Virginia-class submarines to be modified to carry more cruise missiles and develop an undersea conventional prompt strike option,” Defense Secretary Leon Panetta said at a press conference.
Obama administration national security leaders -- like their Bush administration predecessors -- have touted the idea of developing conventional military technologies that could attack urgent targets without having to resort to nuclear-armed ballistic missiles. The capability could be used against terrorist leaders spotted at a safe house or a North Korean ballistic missile being readied for launch, officials have said by way of example.
If the new submarine-based missile plan goes forward, it would be the third such proposed system to receive prompt-strike developmental emphasis. Earlier Pentagon plans for long-range submarine- and ground-based missiles have faced some serious political and technical challenges over the past months and years.
Three main options are now under consideration for pursuing the attack submarine-based capability, Global Security Newswire has learned. Under one possibility, a newly designed intermediate-range ballistic missile could be fielded in two new launch tubes designed initially for carrying Tomahawk missiles aboard the Virginia-class vessels.
A second, more ambitious option would be to install in the attack submarines a so-called “four-pack” missile launcher designed for the Trident D-5 nuclear-armed ballistic missiles on future Ohio-class replacement submarines, also known as SSBN(X). Potentially three of the 32- to 36-inch diameter midrange missiles could fit in each of the four Trident-sized tubes, giving the Virginia-class boats a capability to launch as many as 12 of the conventional ballistic missiles.
This alternative would require a major modification to the attack submarines, namely the addition of a “humpback” midsection behind the sail to accommodate the four-pack launch tubes of significantly greater length than the new Tomahawk canisters, according to defense sources.
A third option -- seen as yet more costly and ambitious -- would be to adopt a design for an even wider Trident-capable launch tube for humpback installation on the attack submarines. This would potentially allow for the medium-range missiles to be larger and have longer range, sources said.
Budget pressures could force the Pentagon to stick with the first option -- assuming that lawmakers are even willing to entertain that possibility, according to Hans Kristensen, who directs the Nuclear Information Project at the Federation of American Scientists.
The relatively small size of these attack submarines, relative to the large Ohio-class “boomer” vessels, could accommodate only a limited-range ballistic missile if the boat’s basic design contours are to remain unchanged, he said.
However, any of these options for fielding a prompt-strike capability aboard submarines is almost certain to spark objections in Congress, which has consistently rejected earlier submarine-based concepts that the Defense Department proposed for conventional ballistic missiles.
Lawmakers have generally supported the idea of non-nuclear “prompt global strike,” Pentagon nomenclature for the ability to attack an enemy anywhere around the world on just one hour’s notice, without resorting to atomic war.
Retired Gen. James Cartwright, who served until last year as vice chairman of the Joint Chiefs of Staff, argued in 2005 that advanced conventional-weapon technologies could allow the nation to "drastically" reduce its nuclear arsenal. One military expert subsequently estimated that conventional munitions were capable of destroying up to 30 percent of targets in the nuclear combat plan (see GSN, May 28, 2008).
However, the U.S. Congress, Russian leaders, and many nuclear strategy experts warned that fielding conventional ballistic missiles on nuclear-capable submarines could be a potentially destabilizing way to carry out the strike mission. According to this view, Moscow or Beijing might mistake a ballistic missile launch from a submarine for a nuclear salvo, and set loose a devastating response.
Citing these concerns, Capitol Hill repeatedly denied funding for an earlier plan to swap out the nuclear payloads for conventional warheads on a limited number of Trident D-5 ballistic missiles aboard Ohio-class submarines (see GSN, Sept. 22, 2010).