Last month, the Congressional Research Service (CRS) released a report on three advanced technologies under development by the U.S. Navy for its surface ships: Solid state lasers (SSL), the electromagnetic railgun (EMRG), and the hypervelocity projectile (HVP). The SSL fires a high-energy beam for short-range defense (one to five miles) against small boats, drones, aircraft, and incoming missiles. The EMRG uses electromagnets to “push” a solid, guidable projectile at over Mach 7 to ranges over 100 nautical miles (nm). The HVP is the round designed for the EMRG, but that can also be fired from existing naval cannons using traditional gunpowder propellant. Shot from a conventional naval gun, the HVP’s range is almost 50 nm—over twice the effective range of current naval artillery, and with substantially greater accuracy.
CRS assesses that any one of these technologies would be a “game changer” if successfully fielded, and that if two or all three make it to the fleet it would be a “revolutionary” development in shipboard warfare. The SSL was intended as a supplement and possible replacement for other shipboard short-range defense systems against incoming missiles or aircraft. The EMRG and HVP, though, were conceived as offensive weapons against other ships or targets on shore in place of expensive missiles and conventional naval cannon. But what makes these technologies revolutionary is their defensive impact and potential to give the U.S. Navy a means to control (i.e. limit) conflict escalation against a peer adversary.
CRS paints a clear picture of the Navy’s current limitations:
[O]bservers are concerned about the survivability of Navy surface ships in potential combat situations against adversaries, such as China, that are armed with advanced ASCMs [anti-ship cruise missiles] and with ASBMs [anti-ship ballistic missiles]…[This] has led some observers to conclude that the Navy’s surface fleet in coming years might need to avoid operating in waters that are within range of these weapons, or that the Navy might need to move toward a different fleet architecture that relies less on larger surface ships and more on smaller surface ships and submarines.
The problem the CRS analysts refer to is A2/AD: anti-access and area denial. Anti-access capabilities are intended to prevent an adversary “access” into a contested area (like the South China Sea) by threatening or destroying ships from outside the theater of operations with ultra-long range weapons, like China’s DF-21D ‘carrier killer’ ASBMs. Area Denial weapons, like China’s increasingly advanced ASCMs (some of which have been recently deployed to contested islands in the South China Sea), threaten or destroy an adversary already in that contested area, thereby “denying” them freedom of action within the theater.
In response to these emerging technologies, the United States began developing the Air-Sea Battle Concept (ASB) to address requirements and plans to “sufficiently shape A2/AD environments to enable…power projection operations…[and] ensure freedom of action in the global commons.” Public information about the classified concept was limited and critics charged the U.S. was developing plans to address a limited threat from China that risked unlimited, potentially nuclear, conflict escalation. Early think tank reports on the concept pointed to the need to strike long-range weapons systems, sensors, and command and control centers based on the Chinese mainland, moves that risked Chinese retaliation against U.S. bases in Japan, Guam, or worse. This extraordinary risk of escalation made the concept appear impractical for any clash less than a full-scale war. The Defense Department ASB implementation plan that was eventually released publically is not as explicit, but its concept of “attack in depth” to destroy enemy A2/AD systems might include mainland strikes. Perhaps recognizing a losing public relations effort that was antagonizing China, the U.S. closed its Air Sea Battle Office in 2015, scrapped the name, and folded its efforts into a new office responsible for the “Joint Concept for Access and Maneuver in the Global Commons.”
The CRS report emphasizes two major limitations on current Navy surface ship defenses in an A2/AD scenario: Depth of Magazine and the Cost Exchange Ratio. Depth of Magazine is the number of missiles or rounds a ship can carry and fire. (U.S. Navy missile capable ships have between 90-120 missile cells, which must hold not only air defense missiles but also land-attack missiles and anti-submarine rockets). Even if a ship can shoot down an enemy missile with its own anti-air missiles or point-defense gatling guns, it is limited in the number of defensive missiles it can carry and the number of rounds its point defense weapon holds. If an adversary’s missiles are not advanced enough to evade that ship’s defensive missiles, they still need only launch more ASCMs than their target has defensive weapons to counter with.
The Cost Exchange Ratio refers to the cost of that adversary’s offensive missiles compared to that of the target ship’s defensive systems. The U.S. Navy fields several highly capable but expensive defensive anti-air missiles. As the report details, the widely-deployed SM-2 is a comparative bargain at roughly $400,000 per missile. Its far more advanced cousin, the SM-6, designed for today’s newer ASCMs, runs nearly $4 million per missile. Meanwhile, the most advanced shipboard counter against ballistic missiles, the SM-3 variants, cost between $14 and $20 million. Lopsided exchange ratios against an industrialized adversary like China capable of building large numbers of offensive missiles means defending Navy ships could become unaffordable in a protracted conflict, especially if the adversary’s advanced missiles require multiple defensive missiles to be shot against them to be confident of a hit.
The trifecta of new defensive systems under development are not only potentially more effective against ASCMs and ASBMs than current missile systems, they practically eliminate Depth of Magazine limitations and have vastly more favorable Cost Exchange Ratios. SSL systems possess an unlimited number of ‘shots’ as long as the ship can generate electricity for the weapon, and, according to CRS, have a marginal cost of about $1 per shot. A ship firing the HVP, whether from an EMRG or conventional naval cannon, can store hundreds of rounds, which cost about $25,000 each.
In a clash with China today, U.S. warships could find themselves either having to 1) abandon a threatened geographic area (thus effectively ceding the conflict), or 2) make pre-emptive strikes against A2/AD systems on the Chinese mainland, virtually ensuring escalation, perhaps uncontrollably. If successful, these new systems would give U.S. Naval vessels far greater defenses in an A2/AD scenario without resorting to escalatory defensive strikes. While a theoretical clash might escalate anyway and require those strikes, it would not be because U.S. warships lacked other choices to defend themselves. Solid state lasers, the railgun, and hypervelocity projectile could thus provide decision-makers an additional ‘off-ramp’ before escalating a limited conflict further, and might even change an adversary’s calculations about starting a clash in the first place.