Considering these factors, it is clear that the importance of the undersea will continue to grow, both in economic and in military terms, for the foreseeable future.
Trends in Undersea Force Structure
Against this backdrop of unique Undersea Force value and continued strong demand we must consider the trends in Undersea Force structure - the long-term number and type of vessels we can expect in our future Undersea Forces. The Navy has worked hard to arrest the downward trajectory in overall Navy force structure and stabilize the Navy near or slightly above its current level. Even this stabilized force, though, includes as part of its baseline a reduction in submarine platforms of more than 25 percent over the next 15 years. This decline is not the result of some recent decision; it is the consequence of budget decisions taken over years and indeed decades. There were only two submarines procured from 1991 to 1998, producing two undesirable results. First, the expertise for submarine construction was dismantled and has only recently begun to recover to full strength. Second, it resulted in the loss of nearly a dozen SSNs in the force. Today's attack submarine force of 55 SSNs will drop to 42; the 4 guided missile submarines (SSGNs) will drop to 0; and the 14 ballistic missile submarines will drop to 10. The total submarine force will drop from 73 to 52 ships -- a cut of 29 percent - before rebounding in the 2030s. The vertical strike payload volume provided by the Undersea Force will drop by well over half. This trough is borne of the submarine shipbuilding hiatus of the 1990s, and no realistic build plan could now prevent it.
Shortfalls in Undersea Forward Presence
Undersea Forces will also suffer degraded forward presence. As a way of maximizing the deployed presence of U.S. nuclear submarines, the Navy uses a different rotational duty pattern for SSNs, SSGNs, SSBNs and Guam-based SSNs. Over the next 15 years, the forward presence of SSNs and SSGNs taken together will fall by over 40 percent. Roughly half of this reduction is due to the decline in the number of SSNs and half is due to the retirement of the SSGNs. One SSN will move to Guam to help mitigate this decline; additional increases in the number of SSNs in Guam, however, are constrained by the unavailability of infrastructure on the island and on the risks associated with concentrating too much of the force in one potentially vulnerable place.
Today, the SSN force is at 55 SSNs -- above the 48-SSN minimum requirement defined by force structure analysis. Despite this nominal excess in SSN capacity, the combatant commander unconstrained demand for SSN forward presence greatly exceeds that which can be provided.
In 2006 Congress tasked the Navy about how it would provide the required SSN forward presence of a 48-SSN Navy with a force that would drop as low as 40 SSNs. In 2007 CNO Mullen testified about the tools available to him to reduce the impact of letting the SSN force dip below the required 48 level. The three tools he outlined were (1) reducing the time to build each VIRGINIA-class submarine to about 60 months; (2) extending the service lives of selected LOS ANGELES-class SSNs beyond 33 years as fuel and material condition allow; and (3) using deployments as long as 7 months to increase deployed availability. Since the first of the Block II VIRGINIAs was delivered in 2008, we have been making significant progress in reducing the construction time of our submarines. Getting to below 60 months on PCU NORTH DAKOTA will help to add one to two effective SSNs to the force level. SSN fuel and material condition are being carefully managed to maximize the chance that some life extensions will be possible. If current trends continue it may be possible to fill about one-third of the ship-years of SSN shortfall. Lengthened deployments above 7 months, as mentioned, are already in use.