The supersonic anti-ship missile was a product of the Soviet Union's need to challenge the U.S. Navy at sea. That speed was a brute-force way to punch through more technologically sophisticated U.S. shipboard defenses. In the years since the collapse of the Soviet Union, a few of these missiles and their platforms — essentially holdouts from the Soviet days — have begun to turn up in China. But a new generation of supersonic anti-ship missiles has begun appearing on the market, and their proliferation is on the rise.

The Threat

Anti-ship missiles have repeatedly proven their value. The HMS Sheffield (D80) was hit by a French-built Argentine Exocet in 1982 during the Falkland Islands War and later sank. The USS Stark (FFG-31) was crippled by a pair of Iraqi Exocets in 1987. And in 2006, the Israeli INS Hanit was struck by a Chinese-built C-802 (a design similar to the Exocet) during the Israeli conflict with Hezbollah. Both the Stark and the Hanit survived, but the missiles achieved what is known as a "mission kill." In each case, though the crew was able to keep the ship afloat and limp back to port, the ship's ability to effectively execute its missions was lost. Modern warships are no longer armored as they once were. In the cases above, the Exocet's 360-pound warhead did not tear the ship apart. But it easily penetrated the steel hull and wreaked havoc on the ship's internal spaces. Not all hits like this will be mission kills, but the odds of one are high — and increase if multiple missiles impact the hull. This is where the new supersonics come in. Their capabilities vary, but they bring two things to this dynamic. First, by significantly reducing the reaction time for shipboard defenses, they increase the likelihood of a successful hit, especially in their sea-skimming variations. Second, their increased speed translates into increased kinetic destructiveness. Even if a missile is destroyed, its fragments can pepper the side of a ship.

The New Market

Three missiles in particular are poised to proliferate more widely:

• The BrahMos: Taking its name from a combination of the names of India's Brahmaputra River and Russia's Moscow River, the BrahMos is the product of an Indian-Russian venture. Its design work can be traced to the Soviet Union's fledgling SS-N-26. Begun in 1985, the design had already been through substantial testing by the time India joined the project. Probably neither the most technologically advanced nor the most maneuverable among the supersonic anti-ship missiles, the BrahMos is principally noteworthy for its availability. It is currently being inducted into service with the Indian military and could soon see a surge in proliferation, with Malaysia as the likely first export customer.
• The AS-17 "Krypton": A late-model air-launched missile with a number of air-to-air and air-to-surface roles, this ramjet-powered missile has already been copied by the Chinese, and the Kh-31A series is being used in an anti-ship role. Despite its significantly smaller warhead, the Krypton is noteworthy for its compact size. Su-30 "Flanker" fighter jets can carry four.
• The SS-N-27 "Sizzler": Another late Soviet design, the Sizzler family (known to the Russians as the "Club") actually encompasses a series of anti-ship, ground attack and anti-submarine missiles. Occasionally known as the SS-N-27B, the anti-ship 3M54 version is of principal interest here, as it includes a sea-skimming supersonic terminal stage that travels at Mach 3 only some 20 feet above the ocean. It covers the last 10 miles of its flight in just over 20 seconds. The guidance systems of this particular missile may be more advanced, and it is thought to have considerable maneuverability in the terminal stage, making it harder to bring down. Its capability was highlighted by the Commander of U.S. Pacific Command, Adm. Timothy J. Keating, when he admitted in testimony before Congress on March 12 that this missile is "a very sophisticated piece of hardware and we are currently not as capable of defending against that missile as I would like." Though it is not always clear that it is the supersonic variant being deployed, the Sizzler family of missiles has begun seeing significant levels of deployment aboard Russian-built Kilo-class submarines purchased by China and India and could be used on more of the Russian fleet as well. Rosoboronexport, the Russian arms-export monopoly, is increasingly marketing the missile as a package with these subs. Venezuela, Algeria and Libya could even find themselves in possession of this capability down the road.

The Defense

Armoring against this threat has not been a design choice for decades. In the 1960s and 1970s, the Soviets began to field supersonic anti-ship missiles with 2,050-pound warheads. This was not a problem to be solved with armor; in addition to the dramatic increase in shipbuilding costs, power plant capability requirements and fuel consumption involved, there was no way to harden a ship — including the superstructure — against such kinetic and explosive destructiveness. Thus, the United States has long relied upon technology to prevent anti-ship missiles from impacting in the first place. The vaunted Aegis battle management system was designed to coordinate these defenses, which by all measures are quite good. But defenses must continually be cultivated, tested and refined. For more than five years, voices in the Pentagon have been clamoring that this is not being done. The problem is targets. After the Soviet Union fell, a variation of the Krypton known as the MA-31 was sold to the United States as a supersonic target. However, the MA-31 never went into mass production, and the small inventory — which is almost depleted — is generally used in a high-altitude powered-dive role, rather than a sea-skimming role. The GQM-163A "Coyote" supersonic sea-skimming target vehicle is currently in production, and the U.S. Navy plans to purchase nearly 40 of them by 2009. While the Coyote might be a near-term acquisition solution, it does not entirely approximate the Sizzler's subsonic approach and supersonic terminal profile (the Defense Department calls this profile "Threat-D"), and the Pentagon has not had a good supersonic target for some time. Keating's candor before Congress seems to reinforce the apparent fact that shipboard defenses are not being refined as highly as they could be.

The Problem

This is troubling on two fronts. First, the U.S. Navy's shipbuilding plan, which calls for a 313-ship fleet, remains in serious near-term question. Ship numbers are dropping, and the next-generation DDG-1000 guided-missile destroyer and Littoral Combat Ship (LCS) are both over budget and behind schedule, while the number of attack submarines in the inventory continues to decline. This makes each individual hull more valuable. But second, and more importantly, the U.S. Navy has long worked under the assumption that technologically advanced air defenses can provide sufficient protection from these threats. While it is clear that armor probably is not the solution for a navy already struggling to make ends meet in shipbuilding, the inability to prove upgraded shipboard defenses in representative live testing should be a matter of grave concern, especially since these threats may necessitate alterations to tracking software and engagement profiles. The U.S. Navy retains its global maritime supremacy, and no other nation is in a position to even think about competing in the near term. But modern navies have repeatedly been stung by anti-ship missiles launched by lesser military powers. And this proliferation of a new generation of supersonic anti-ship missiles promises that technologically advanced shipboard defenses have not been tested for the last time.