Well-armed coastal powers have numerous advantages in coping with hostile naval forces, but the shortage of funding for modernization suggests that most of the Navy's near-term experience with littoral warfare will be acquired using vessels designed and built during the Cold War vessels configured primarily for coping with the Soviet Navy in the open seas. Major modifications already are being introduced into these ships to enhance their operational utility in littoral warfare. Some, such as the efforts to increase the volume, precision, and coordination of offensive firepower, are very promising. Other initiatives, such as improving survivability, are more problematical. The challenge is complicated by the fact that future adversaries are likely to share many of the benefits of the revolution in digital technologies.
Against this backdrop, one proposal for recycling a Cold War weapon system seems to hold particular promise for enhancing the firepower and survivability of naval elements operating in the littoral. That is the idea of converting surplus Trident ballistic-missile submarines (SSBNs) into platforms for the launch of conventional guided missiles against land targets-in other words, into SSGNs. The large volume of the Trident would enable it to carry as many conventional cruise and/or ballistic missiles as an entire carrier battle group (100-150 missiles), and its survivability would allow it to operate in close proximity to hostile littoral powers without support from other naval assets. In addition, the Trident SSGN would be affordable because the vessels, their bases, and many of the needed weapons already have been purchased.
The Ohio (SSBN-762) class was conceived in the early 1970s as a more potent successor to Polaris-Poseidon nuclear deterrent submarines. Each boat carries 24 intercontinental-range ballistic missiles capable of delivering eight (or more) kiloton-range warheads against separate targets. To accommodate this large complement of weapons, the Trident has a bigger internal volume than any other U.S.-designed submarine. And because stealth and survivability are essential to its effectiveness in the nuclear deterrence role, it is equipped with a sophisticated array of active and passive defensive measures suitable for countering surface and submarine threats.
The last of 18 Ohio-class submarines was commissioned on 6 September 1997, culminating an acquisition program praised by the General Accounting Office as one of the best-managed in modern naval history. But by the time construction of the final boat was approaching completion, it was apparent that fewer than 18 Tridents would be needed for the nuclear deterrence mission. In the 1991 Strategic Arms Reduction Talks (START I), the United States and Russia agreed to cut the number of nuclear warheads in their strategic arsenals from 13,000 and 11,000, respectively, to 6,000 each. A subsequent START II agreement called for further reductions to 3,000-3,500, and in March of this year, the two countries tentatively committed to a follow-on pact that would shrink each nation's strategic arsenal to 2,000-2,500 warheads by 2007.
The Russian Duma has not yet ratified the START II agreement, but there is growing support among U.S. decision makers for implementation of the lower warhead levels in advance of ratification. Because many of the weapons in the reduced U.S. strategic force are expected to remain on land-based missiles and bombers, a portion of the Trident force would need to be retired to comply with the arms agreements. The first step in this drawdown process was set forth in the 1994 Nuclear Posture Review, which called for a reduction in the Trident force to 14 boats.
The four oldest Tridents-the Ohio, Michigan (SSBN727), Florida (SSBN-728), and Georgia (SSBN-729)are scheduled for removal from service in 2002-2003, and thus would be available then for conversion to the SSGN configuration. In the baseline design the Navy currently is contemplating, 22 of 24 missile tubes would be converted to carry 6 conventional missiles each, for a total of 132 missiles per boat. These would be either land-attack variants of the Tomahawk cruise missile or naval versions of the Army Tactical Missile System (NTACMS), a short range (limited by START agreements to 300 nautical miles) ballistic missile that provides quick-response options for attacks against enemy infrastructure, armor, and hardened command centers.
The remaining two missiles tubes would be converted to lockout/lock-in chambers for special-operations forces that would enable the 66 SEALs accommodated on the Trident to access two swimmer-delivery systems attached to the outer hull.
According to industry estimates, all four conversions could be accomplished over a ten-year period, from 1999 to 2008, for approximately $1.5 billion. This would cover refueling, weapon-system modifications, additional hardware, design services, and other labor-all for an annual expenditure comparable to the overhaul of one attack sub.
Part of the appeal of using Tridents in the conventional land-attack role is that, unlike the arsenal ship, they could do more than simply attack land targets. Proponents view it as a multirole boat that could accomplish several missions spanning every phase of littoral conflict. The proposed design would retain all of the SSBN's tactical-surveillance and intelligence-collection equipment, enabling it to conduct reconnaissance both prior to and during hostilities. It also would retain the SSBN's antisubmarine and antisurface warfare capabilities, which include the full range of sensors and torpedoes needed to track and destroy enemy combatants. A key criticism of the arsenal ship has been its lack of self-defense capability, a defect from which the Trident SSGN clearly would not suffer.
The ability of the Trident SSGN to host four platoons of special-operations forces-plus their delivery systems and specialized gear-adds an important dimension to its warfighting utility in the littoral. This particular aspect of naval warfare would need to be addressed even in the absence of an SSGN proposal, because the Navy's two dedicated special-operations submarines-the Kamehameha (SSN-642) and the James K. Polk (SSN-645)are approaching retirement. Trident SSGNs not only would provide new host vessels for SEALs, but by combining the SEALs with other on-board capabilities, also would create a very versatile littoral-warfare platform. The SEALs (more than one hundred could be accommodated on board for short periods) could be employed in littoral-warfare missions ranging from reconnaissance to preparation of the battlespace to hostage rescue. They also could contribute significantly to the SSGN's success in its primary role, for example by covertly obtaining precise targeting intelligence concerning key enemy assets.
It is the land-attack mission, however, that drives the SSGN concept. Navy proponents see many advantages that few alternatives could match. First, the Trident SSGN would enable the Navy to accomplish non-provocative forward presence by stationing in close proximity to regional aggressors potent firepower that would be very difficult to detect, much less track and engage. Second, because these aggressors would not know when and where SSGNs were in their area, their planning would be greatly complicated. The uncertainty surrounding such a situation in which retaliation against aggression could occur at any time, with no effective way to prevent or preempt it would be a powerful psychological deterrent.
In the event hostilities occurred, the Trident SSGN would have additional virtues. Because it could be covertly forward deployed, it probably would be the first combatant in theater. In that role it could contribute quickly to achieving early air and sea superiority by striking the most militarily sensitive and time-critical targets. Its stealth would enable it to leverage the element of surprise, maximizing targeting effectiveness, minimizing the likelihood of weapon interception, and throwing enemy leadership off balance. Depending on the nature of the conflict on land, it also might help halt an enemy invasion of a friendly nation, or at least impede the invasion's progress until other U.S. and allied military forces arrive.
Prior to the arrival of other forces, the Trident SSGN would be able to engage in covert, autonomous operations without support from other naval assets. In situations involving protracted tensions or lack of access to the theater by other U.S. forces, it could operate securely and independently for up to three months. Once follow-on forces did arrive, command, control, and communication upgrades planned for the SSGN would enable it to make an important contribution to joint task force operations.
More generally, the Trident SSGN would satisfy a pressing military requirement with a proven platform that has an established infrastructure and support system. Once converted, the Tridents would be ready for 20 years of new service. They would offer the Navy enhanced lethality, survivability, and versatility in the littoral for a generation at a fraction of the cost of designing and building new warships.
Planners could squeeze maximum military utility out of the four Trident SSGNs by imitating the dual-crew concept employed for ballistic-missile submarines. Two SSGNs would be stationed on each coast at the existing Trident support facilities in Bangor, Washington, and Kings Bay, Georgia, and each boat would be assigned a Blue and a Gold crew. The SSGNs on the West Coast would cover patrol areas in the Pacific and Indian Ocean littorals, and those on the East Coast would be assigned to the Atlantic and Mediterranean littorals. By carefully coordinating the two crews on each vessel with transit and refit schedules, the Navy could maintain one SSGN from each coast on station near foreign flashpoints more than 75% of the time. A less expensive manning concept allocating only one crew to each of the four SSGNs would allow two boats to be station about 50% of the time.
Proponents of the SSGN concept see it not only as a cost-effective way of meeting future military requirements but also as an opportunity to implement emerging technologies and warfighting concepts in the littoral. For example, senior Navy officers recently have advanced the notion of "network-centric warfare," a way of conducting naval operations that places less emphasis on specific platforms than on the aggregate capability that is achieved by linking all assets in a common command, control, and communications architecture. Supporters contend the Trident SSGN could fit seamlessly into such an architecture by using newly available digital systems that keep it in constant contact with other naval elements. These links would permit the Navy to exploit the survivability, endurance, and operational autonomy of the SSGN, while still fitting it into a broader framework of agile command relationships and distributed firepower.
Presumably, the Trident SSGN also would benefit from other advances in warfighting technology gradually being applied to littoral warfare. These include the use of unmanned undersea and aerial vehicles to enhance the situational awareness and reconnaissance capabilities of submerged vessels. Real-time links to other assets such as the JSTARS airborne synthetic-aperture radar system would enable the commander of the SSGN to use his weapons and special-operations forces with maximum effectiveness against mobile, concealed, or hardened targets ashore. When these emerging capabilities are combined with the stealth and endurance of the Trident SSGN, the result is a quantum leap in littoral warfare potential.
In the broadest sense, the Trident SSGN proposal reflects the gradual redefinition of the warfighting roles assigned to various Navy platforms in the post-Cold War period. It exploits new technologies and operational concepts in a manner that blurs distinctions between traditional service communities and missions, producing a system that is well-suited to future littoral warfare requirements and yet remarkably affordable.