The modern nuclear-powered attack submarine (SSN) is a heavily armed, highly versatile — and enormously expensive — platform. For decades, the Cold War drove their development and monopolized their application. But their principal purpose, hunting an adversary's subs, largely evaporated with the collapse of the Soviet Union. So what are today's SSNs good for? The SSN has its roots in purely naval confrontation, and was developed by both the United States and the Soviet Union. Both countries sought to project covert naval power far from their respective territorial waters. U.S. SSNs regularly operated all the way into the Soviet Navy's backyard, where they stalked ballistic missile submarines (SSBNs) in what was known as strategic anti-submarine warfare. The height of SSN design is the U.S. Seawolf-class (SSN-21). A product of the waning days of the Cold War, when late Soviet SSN designs were then making serious inroads against the qualitative U.S. advantage in SSNs that had stood for decades. Indeed, the Seawolf restored a generational lead in terms of acoustic signature and capability. But despite its ongoing reign as the most deadly SSN on the planet, only three were built due to their massive cost and the tectonic shift in geopolitics following the Soviet collapse. Like so much else in the post-Cold War era, the flexibility inherent in a modern SSN has become a mission in itself — one embodied in the U.S. Virginia-class (SSN-774) design. While still massively expensive, the Virginia design was tailored in part to the variety of "peacetime" missions regularly assigned to modern SSNs, including:
- Intelligence, surveillance and reconnaissance (ISR). In short, this is the ability to loiter undetected off a coastline and monitor all manner of electronic and acoustic traffic, not to mention monitoring a potential adversary's coastal submarine activity.
- Operation as a strike platform. Equipped with twelve vertical launch system (VLS) tubes, each Virginia-class sub (along with the 31 Improved Los Angeles-class boats) is a covert strike platform for Tomahawk cruise missiles. Later Virginia variants may significantly expand this capacity.
- Special operations insertion. Using swimmer delivery vehicles, Virginia and select Los Angeles SSNs are capable of inserting small SEAL detachments anywhere in the world.
- Anti-submarine escort. In one of their more traditional roles, SSNs still regularly accompany carrier strike groups and expeditionary strike groups in part for their value as anti-submarine warfare platforms. These days, the sub is also generally equipped with the VLS.
- Strategic anti-submarine warfare. Though there is little current demand for this traditional mission, Russia's resurgence and developments in China will likely require increased vigilance in this area in the foreseeable future.
