The U.S. Navy’s Big New Missile Mod: What Friends and Foes Should Know


Bitter tears are being wept in Beijing, Moscow, and other hives of scum and villainy around the world. Last week, Secretary of Defense Ash Carter delivered heartwarming news for any U.S. Navy surface warrior — indeed, for anyone who wants America to shore up its strategic position in Eurasia. The surface fleet has acquired a new anti-ship missile almost overnight. Secretary Carter announced that weaponeers have secretly repurposed and tested the SM-6 — the latest version of the Standard Missile that has guarded task forces against aerial assault since the 1960s — for use against fellow surface armadas.

The SM-6 gambit helps redress a dangerous shortfall in the surface fleet’s arsenal. Since the Cold War, the U.S. Navy and Air Force have grown accustomed to “standoff” weaponry. Gee-whiz bombs and missiles, that is, boasting such range and precision that U.S. ships and aircraft can strike targets from a safe distance. Outranged foes never get off a shot because their firing range is too short. Hence the low casualty figures among U.S. mariners and airmen during post-Cold War conflicts.

Trouble is, standoff logic works both ways. Anti-ship missiles comprise the surface fleet’s main battery these days — its principal armament for reaching out and touching enemy men-of-war. After the Cold War, however, the U.S. naval establishment took a holiday from upgrading the fleet’s anti-ship armament. No new anti-ship cruise missile has entered service since the early 1990s. Indeed, the Navy dismantled an anti-ship variant of the Tomahawk cruise missile in 1994 — drastically shortening the fleet’s reach.

Such developments did not go unnoticed around the world. If foes arm their fleets with missiles that outrange U.S. weaponry — and they have — they can strike at American formations while remaining out of harm’s way. They too can harness the logic of standoff warfare. If U.S. naval commanders opt to close to missile range — as they must to prevail — they have to endure punishment from enemy missiles along the way. Weapons range, then, is the great equalizer for opponents that may not match up against the U.S. Navy on a ship-for-ship basis.

Think about what boosting a warship’s striking range does. Pull out your nautical chart, pick your favorite world hotspot, and suppose a ship is cruising at a given point nearby on the chart. Now sketch a circle around that point, setting the radius on your compass equal to the maximum firing range of the rangiest weapons system carried aboard that ship. Increase the range and you increase the radius. Increase the radius and you increase the ship’s geographic coverage. That’s high-school geometry.

But as our geometry teachers observed, the area of a circle grows by the square of the radius, not in direct proportion to it. Doubling the weapon’s range multiplies the sea area reachable by the vessel’s main battery fourfold. Tripling it multiplies the area ninefold. Chances are, the SM-6 will at least double the engagement range of U.S. Navy large surface combatants. The SM-2ER — the predecessor of the SM-6 and the last Standard Missile to be outfitted with an anti-ship capability, and a workhorse of fleet air defense to this day — has a listed range of 200 nautical miles. While the SM-6’s range remains classified, it’s probably roughly comparable to that of the SM-2ER. If so, it will at least double the 60 nautical mile range of the Harpoon, the fleet’s current standard anti-ship missile. This is a big deal.

Adding more ships to the hypothetical formation augments its ability to execute strategies based on what seapower theorist Julian Corbett calls “elastic cohesion.” Corbett urged fleets to spread out to police large expanses while remaining close enough to “condense” combat power at likely scenes of action at short notice. (Or, if you prefer, Corbett’s contemporary Alfred Thayer Mahan likens the optimal disposition of a fleet to a fan opening and shutting.) Dispersal magnifies the sea areas patrolled. Concentration musters superior force where and when it’s needed.

Adroit naval commanders, then, try to have it both ways. Managing concentration and dispersal of assets, writes Corbett, renders the fleet “a compound organism controlled from a common center, and elastic enough to permit it to cover a wide field without sacrificing the mutual support of its parts.” Ships with greater reach can concentrate firepower for battle from greater distances. Increasing shipboard weapons’ range gives the fleet new elasticity, resilience, and all of the other goodness that comes from sound strategy. Sir Julian would smile.

It’s no stretch to say the U.S. Navy’s operational and strategic effectiveness hinges on restoring its edge in this domain. The first, foremost, inescapable function of any navy is to wrest command of the sea from enemy navies by sinking them or driving them from important waters. It’s tough to be a global force for good when you can’t defeat foes bent on thwarting your operations.

Furthermore, think about peacetime naval diplomacy. Deterrence and coercion depend on making believers out of your opponents. Convince them you would win in combat, and your chances of deterring or coercing without firing a shot brighten. On the other hand, the U.S. Navy will find it hard to cow prospective antagonists that question its battle prowess. Reassurance also flows from combat capability. If enemies fear a winner, friends love one. Few allies take comfort in security guarantees from allies that can’t ride to the rescue in wartime.

So restoring the reach of U.S. Navy warships matters on many levels. Now, it’s important not to get too swept away with the SM-6 news. First of all, it’s doubtful a “bird” designed to bring down aircraft and missiles will represent a true shipkiller. Few ever deluded themselves that the SM-2’s “limited” anti-ship capacity was an adequate substitute for a purpose-built anti-ship missile. Air defenders, moreover, may be loath to divert air-defense rounds into anti-surface missions for fear of exposing the fleet to air or missile attack.

Like the SM-2, the SM-6 is a speedy missile, meaning kinetic energy will amplify its punch. But its blast fragmentation warhead is probably too small to sink major warships. A “mission kill” that temporarily disables an enemy is a more reasonable prospect. That’s an improvement over nothing at all, but not enough to fully restore the U.S. advantage in surface warfare. Adding an anti-surface capability to the SM-6 is a gap-filler — not a panacea.

Second, there’s the question of cost. Standard Missiles do not come cheap, and the SM-6 is no exception. With an estimated cost of upwards of $4 million per round, it is doubtful crews will get many practice shots in anti-surface mode (or, for that matter, in anti-air or ballistic missile defense modes). The advent of an SM-6 anti-surface capability, moreover, sets up a zero-sum competition between anti-surface, anti-air, and missile defense missions. How will commanders assign missiles to cope with a multidimensional threat along multiple axes when the fleet faces attack both from surface ships and from aloft? Gunners become proficient by doing. Developing, refining, and practicing tactics and doctrine is tough when you seldom get to fire your weapons.

And third, ships equipped with vertical launch systems (VLS) — in effect missile silos built into the hull — have very finite missile stockpiles. Aegis cruisers have around 120 VLS cells, Aegis destroyers under 100. Nor can VLS cells be reloaded at sea — meaning that ships go to war with the missile loadouts they have. Commanders must determine in advance whether they’re likely to fight for command, pummel enemy shores, or what have you. That will shape how many SM-6s, SM-2s, and Tomahawk land-attack missiles they assign to surface combatants. In effect, commanders must gamble on the complexion of the tactical setting, apportioning missiles for probable threats. How naval commanders will manage magazine loads remains to be seen.

Lastly, and most importantly, practitioners and pundits must resist the urge to breathe a sigh of relief over the SM-6’s debut as a surface-warfare implement. This is not the end of strategic maritime competition with China, Russia, or anyone else. Indeed, there are few final victors in strategic competition. The Navy, accordingly, must press ahead vigorously with its quest for true anti-ship weapons, notably the long-range anti-ship missile currently under development for fielding aboard aircraft in 2019, and the anti-ship variant of the Tomahawk tested last year. The Navy will hold a competition in 2017 to determine what missile will become its standard shipboard anti-ship weapon.

This is a fateful choice. Naval competition is a process of constant interaction and one-upmanship. Serious opponents won’t become disheartened and abandon their ambitions just because the United States restores some of its hardware advantages. They will keep trying to undermine those advantages while amassing advantages of their own. And on and on the cycle goes.

The U.S. Navy’s predicament stems from an unforced error a quarter-century ago, when the leadership declared, in effect, that the Soviet navy’s demise had rendered moot that most basic function of navies, dueling rival fleets for command. False. And yet that’s when the Navy started letting capabilities like anti-ship missiles decay. One hopes today’s leadership learns a lesson from past neglect — namely, that naval competition may undergo the occasional lull as competitors decline or, as in the Soviet case, fall. It does not go away. The next major competitor will come, sooner or later.

The Navy, accordingly, must constantly strive to bolster its combat capability — not just when peer competitors are plying the waves, but when peace appears to be at hand. An easy fix like repurposing a missile may not suffice next time.


James Holmes is Professor of Strategy at the Naval War College and coauthor of Red Star over the Pacific. The views voiced here are his alone.


Photo credit: Mass Communication Specialist 2nd Class Devon Dow, U.S. Navy