How many ships does the U.S. Navy need to accomplish its goals? Tough to say. Sometimes it feels as though all I do is count ships and airplanes for a living. You'd think there would be no simpler chore than toting up rival navies' strength and calculating who wins and who loses in sea combat. After all, it's elementary-school arithmetic. But you would be wrong. Estimating relative naval strength is harder than tallying up numbers of hulls, airframes, and munitions.
And it's harder by an order of magnitude.
That's because high-seas competition is not a game of Battleship, an enterprise governed by rules and artificial constraints. Unlike the board game, sea combat doesn't pit fleets of identical size and firepower against each other on a featureless oceanic battleground with fixed boundaries. Seldom are commanders intimately familiar with an adversary's order of battle. No one exchanges fire in orderly fashion. Each side tries to pile up comparative advantages in numbers, capability, land-based fire support, and tactical excellence—biasing the outcome in its favor.
Few victors fight fair.
The multifaceted, ambiguous, impassioned nature of maritime war explains why experts still bicker about controversies such as how strong the Soviet Navy was. If the science isn't settled about how an erstwhile foe matched up—if we can't predict how some past conflict would have turned out, even after the facts are in—how likely are we to gauge future opponents' strength accurately? How likely are we to calibrate our naval strength precisely, buying just enough forces and manpower to overcome foes without wasting taxpayer dollars?
Not very. And the consequences of discovering a shortfall could be dire. Better to field surplus capability rather than run a deficit that's exposed only amid the din of battle—too late, in other words.
That rule—err on the side of excess naval power—applies in peacetime and wartime alike. Let's look at peacetime nautical diplomacy first. Deterrence is the peacetime U.S. Navy's chief purpose. After the navy faces down aggression, it does the wonderful things navies can do with freedom of the sea. Showing the flag in foreign seaports, alleviating human misery following natural disasters or other emergencies, scouring the sea of unlawful trafficking—such worthwhile endeavors depend on free use of the global commons.
Deterrence demands physical might, to be sure, but it's about more than tabulating numbers of ships and warplanes. It's about issuing threats and flourishing the wherewithal to follow through on them. Henry Kissinger defines deterrence as amassing heavyweight capabilities, displaying the resolve to use them, and convincing an opponent we have the resolve to use those capabilities should he defy our will. That's a product, not a sum: if any factor is zero, so is deterrence.
It behooves naval officials and officers intent on deterrence to drive up those three variables—capability, will, belief—as high as possible. To impress rivals with one's material prowess, heed a proverb from strategist Carl von Clausewitz: "The best strategy is always to be very strong; first in general, and then at the decisive point." Sounds a bit like buy low, sell high, right? It's common sense. Want to win a test of strength? Hie thee hence to Gold's Gym and make yourself musclebound!
But like all good proverbs, this one's at once simple and profound. Creating strong forces—making the nation's military "very strong," to repeat Clausewitz's words—is the province of society and government. Lawmakers and government officials decide what kind of navy toprovide and maintain, and how abundantly to furnish it with manpower, equipment, and armaments. Once a fleet is fitted out, mustering sufficient might at the decisive place and time to stare down or vanquish adversaries becomes the province of sea-service commanders.
Deterrence, then, demands both forces in being and the artistry to harness them for operational and strategic effect. In a sense this is what Clausewitz calls a "war by algebra," a passionless struggle whereby the correlation of forces determines the result. It's war by the numbers. Whoever boasts the most and most potent implements of war tends to prevail—chiefly by persuading the opponent and bystanders the outcome would be a foregone conclusion were battle joined.
Or as strategist Edward Luttwak puts it, the victor in peacetime encounters is whoever observers think would have won in wartime. How can Washington convince onlookers it would win? Well, it could field a U.S. Navy of unchallengeable size and capability. A big, capable navy can deter even if the bulk of the fleet is dispersed, remote from hotspots, or both. The United States, that is, can discourage mischief if would-be aggressors know U.S. commanders can bring overbearing combat power to bear.
Virtual deterrence comes with a world-beating navy—if you can afford one. Let's say a local antagonist outmatched an American naval detachment—say, the Japan-based Seventh Fleet. Deterrence might hold anyway if the antagonist were certain that the remainder of the U.S. Pacific Fleet would soon fight its way into the theater to reverse the result. If it were clear that any victory would be fleeting, he might refrain from provocative actions in the first place. Why bother?
Short of constructing an unbeatable navy, naval officials could concentrate an outsized fraction of a lesser fleet on the expanses that matter most. That would mean setting priorities among theaters, exercising the self-discipline to stick with them, and telegraphing them to foreign audiences that need deterring. It would also mean admitting that some theaters matter less, and letting allies and partners in secondary theaters know they'll have to make do without Big Brother. Trying to be all things to all friends around the world is a hard habit to break for a superpower.
So much for the factors that muddle the process of fleet design. How big should the inventory be for peacetime purposes? Well, the number of hulls counts most in a war-by-algebra, whether they're on scene or over the horizon. It conveys power and resolve. The more numerous fleet holds the advantage in a contest for political impressions. But size and even capability aren't everything. Luttwak observes that a ship's outward appearance can augment or detract from its political impact—especially its impact on lay audiences.
A fighting ship festooned with guns and missile launchers may make a political sensation, then. Its more lethal peer may underwhelm if its combat punch resides in flat, unobtrusive vertical launchers embedded in its decks. Ho, hum.
How much is enough, then? There's no fixed rule or ratio. The quantity of assets, their fighting power measured in objective terms, and how darned awesome they look all shape the outcomes of peacetime showdowns. The narrower the U.S. Navy's margin of superiority along any of these axes, the smaller its chances of deterring mischief. The more, better, and more impressive its platforms, the easier it is to make an antagonist a believer.
Next time we'll return to this topic, considering how many ships the navy needs in times of strife.
James Holmes is Professor of Strategy at the Naval War College and coauthor of Red Star over the Pacific, an Atlantic Monthly Best Book of 2010. He is RCD's new national security columnist. The views voiced here are his alone.
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