The U.S. Navy's 54 nuclear-powered attack submarines (SSNs) are among the U.S. military's most critical assets. They are involved in nearly all aspects of national security. Undetected, they gather intelligence, insert special forces, and are among the first to fire in times of conflict. Yet the President's budget request for fiscal year 2006 cuts funding that would keep two additional submarines in the fleet. Congress should restore these funds.

Despite warnings in recent years from U.S. Navy officials, the Joint Chiefs of Staff, and the Defense Science Board that the U.S. needs more submarines, the Pentagon's budget could lead to fewer. At a time of increasing and often unknown threats, the Administration should be strengthening the submarine fleet.

Three Los Angeles-class subs were scheduled to be refueled and overhauled in 2007. However, because the President's 2006 budget cuts funding for two of these overhauls, those subs will be lost. This is misguided because, while attack submarines are among America's most critical assets, they are also among the most expensive. The new Virginia-class subs cost over $2 billion each. By refueling older but still very capable Los Angeles-class subs, the Navy can get over a decade of use for only $200 million per submarine.

Furthermore, the Navy's submarine force structure is on a downward trajectory. It will soon begin losing submarines far more rapidly than they are being built. Most of the sub force was procured during the late 1970s and 1980s, when the U.S. was purchasing three and four subs per year. As these reach the end of their useful life, they will leave the force at the same pace, causing significant pressure on the force. Refueling some submarines will help to reduce that pressure.

The Enduring Role of the Attack Submarine. During the Cold War, attack submarines were tasked with tracking Soviet ballistic missile submarines, destroying them if necessary, and collecting intelligence. Although the Soviet Union no longer exists, many of its submarines do. While financial constraints have forced Russia to dock most of its force, it has maintained portions of it that could be deployed in the future.

Other nations also have submarine fleets. China's roughly 70 submarines include one ballistic missile submarine and five nuclear-powered attack subs, and more are in production. China will also be able to upgrade its forces with new technology if Europe lifts its arms embargo on China. North Korea has the world's fourth largest submarine fleet, with 26 diesel submarines that operate in the Sea of Japan and up to 50 smaller subs. Iran has six submarines, including three advanced Russian Kilo-class diesel subs.

Since the end of the Cold War, the U.S. submarine fleet has been asked to do much more than track and counter other submarines. For example, during the first Gulf War and again in 1997 and 1998, submarines launched cruise missiles at Iraqi targets. SSNs launched cruise missiles at Bosnian targets in 1995 and fired 25 percent of the Tomahawk missiles that were used in the Kosovo conflict in 1999. They are also used for limited strike missions, such as those against suspected terrorist camps in Afghanistan in 1998 and suspected chemical weapons facilities in Sudan. Since September 11, 2001, the SSN's role has grown to include providing critical presence, intelligence, and firepower in the war on terrorism.

The National Security Imperative. A robust fleet of attack submarines is imperative in today's world. In war, especially in distant regions of the world where the United States has vital national interests, forward-deployed attack submarines can mount the first line of defense against advancing enemy forces or provide the initial salvo of a surprise offensive. They can prevent the enemy from gaining an early stronghold before other U.S. forces arrive to establish control.

• Warfighting. The key strategic value of attack submarines is that they can be the first military assets to reach a theater of combat and can remain there largely undetected for an indefinite period. They are invulnerable to anti-ship cruise missiles.
  
  As these weapons proliferate and become more precise, the U.S. Navy's surface ships will become increasingly more vulnerable. This makes the stealthy SSNs even more important to the military's future force structure. Moreover, SSNs can clear the way into a theater of combat by destroying enemy weapons and systems that could target surface ships and airplanes. Finally, unlike land-based units and surface ships, the SSN is self-contained and therefore is not vulnerable to chemical or biological attack.
  
  
• Intelligence, Surveillance, and Reconnaissance. Since the end of the Cold War, the fleet's intelligence, surveillance, and reconnaissance missions have increased significantly. Tapping underwater fiber optic cables, intercepting communications signals, collecting water and air samples, spying on military exercises, and monitoring ballistic missile tests are the types of missions that SSNs can conduct off the coasts of regions of strategic interest.
  
  Unlike these SSN activities, other forms of intelligence gathering can be evaded. For example, a rogue state can avoid surveillance by satellites because it can predict when a satellite will pass overhead and simply hide its activities. As more nations acquire sophisticated information networks, terrorist organizations become stronger and larger, and weapons of mass destruction proliferate, intelligence-gathering missions become increasingly important. The need for military assets such as the SSN that can gather this intelligence undetected is great.

Conclusion. Many of America's adversaries are gaining access to modern submarine technology, advanced reconnaissance capabilities, satellites, precision munitions, and ballistic and cruise missiles. However, none of them has the ability to detect submarines or defend against them. In this dangerous world, the value of America's SSN attack submarine fleet cannot be overestimated. Although other naval platforms can perform some of the SSN's functions, none can perform them all. More important, none can perform them undetected. This is why Congress should restore funding to refuel two additional submarines in 2007.

Jack Spencer is Senior Policy Analyst for Defense and National Security in the Kathryn and Shelby Cullom Davis Institute for International Studies at The Heritage Foundation.