Key point: Battleships once ruled the seas before becoming obsolete. The age of the aircraft carrier won't last forever, either.

Iowa-class fast battleships were castles of steel built for an era of flux in naval warfare not unlike our own. In fact, battleship history casts doubt on the future of über-expensive behemoths like the U.S. Navy’s Ford-class nuclear-powered aircraft carriers (CVNs). The question isn’t just whether the aircraft carrier is obsolete, a floating target in the missile age. That reduces the question to technology. The question is whether the carrier is worth its cost in strategic and political terms. If flattops remain survivable enough to bear the brunt of dueling the Russian Navy or China’s People’s Liberation Army Navy for maritime command, they may remain a worthwhile investment.

If not, the carrier fleet’s outlook darkens. Taxpayers and their elected representatives have priorities, winning foremost among them. Justifying carriers’ expense is tough if other implements of war—submarines, small surface craft, whatever—will fight for maritime supremacy while carriers shelter out of harm’s way until the seas and skies are safe enough for them to do their work. Try explaining to the American people or Congress why they should plunk down $15 billion for a single hull when that hull won’t do the heavy lifting in combat. CVNs might still have value, in other words, but not enough to justify their mind-boggling price.

That was battleships’ fate. They never lost their value as fleet workhorses, even after naval aviation displaced them from frontline status during World War II. While battleships remained in the inventory, navies found uses for them. And why not? They had been bought and paid for. They served intermittently into the early 1990s. But new ones were never built. Nowadays few—not even the most fervent enthusiasts—argue for constructing new dreadnoughts. Their price would run to many billions per copy, a forbidding sum for a warship expected to play only a secondary part in sea battles.

A similar fate may await the CVN. The Ford-class may not be obsolete. But other ships or weapon systems could eclipse the CVN as a combat platform—meaning taxpayers would find themselves paying exorbitant sums for a nice-to-have but ancillary capability. That would make little budgetary sense.

You have to credit interwar naval architects for foresight. Conceived during the 1930s, the Iowa class was the Swiss army knife of dreadnoughts. Warship design is a matter of managing tradeoffs among speed, protection, and armament. Back then it remained unclear whether advances in aircraft design would superempower carrier warplanes, extending flattops’ striking range and hitting power. (Spoiler alert: yes.) Shipwrights hedged against uncertainty, drawing up blueprints for a ship class versatile enough to flourish in a variety of potential futures.

The four sister ships constituting the Iowa class boasted firepower and rugged construction sufficient to reprise the role played by armored capital ships for the previous half-century—dishing out and taking punishment in a firefight against battlewagons from the Imperial Japanese Navy or German Kriegsmarine. If armored dreadnoughts remained capital ships without peer—the fleet’s chief repository of battle strength—then the Iowa class was fit to don that mantle. If not—if naval aviation fulfilled its promise—then Iowa-class battlewagons housed steam propulsion plants powerful enough to let them keep up with fast-moving aircraft-carrier task forces.

Iowa designers, that is, constructed gunships able to provide value in a world where naval aviation ruled the oceans. Like past battleships, Iowa-class vessels were fitted with gunnery, radar, and fire control heavy-hitting and accurate enough to conduct shore bombardment. Battleships went on to support amphibious landings throughout the Pacific, Mediterranean, and Atlantic theaters of World War II, as well as fleet engagements against Japan. The fledgling class of battleships, in other words, could contribute to the fight for sea command, regardless of what the future held. And they could perform a variety of functions once command belonged to the U.S. Navy. Iowas were as complete a package as designers could devise.

Hedging—diversifying a vessel’s portfolio of functions and technical attributes to fit a variety of circumstances—only makes sense. For instance, interwar submarine designers intended the U.S. Navy’s Gato-class fleet boats to raid Japanese battleship or cruiser formations. But Gatos could also assail mercantile shipping if deftly handled. These were midsized boats with middling capability by such metrics as tonnage and cruising range. Design choices suited them for a variety of missions—reducing the likelihood that some future evolution of sea warfare would render them useless. Enterprising skippers ravaged Japanese merchantmen throughout the Pacific Ocean.

Indeed, Gato-class subs rank among the most successful classes ever to take to the depths. Their combat performance is a tribute to the naval architects who dreamt them up. There is more to fleet design than newfangled widgets. Hedging is an art—and an attitude—worth rediscovering.

Now look at ship design through the prism of sea-power theory. Maritime strategy comes in threes for historian Julian Corbett. Roughly speaking, naval wars unfold in three phases. A weaker navy can dispute a stronger navy’s command of important waters, denying the opponent victory while buying time to turn the tables and make itself the stronger contender. A stronger navy bids for maritime command when opportunity beckons. It strives to solve a multitude of problems in an afternoon. And, having won command of important waters, the victor reaps the fruits of victory. It enjoys options such as landing troops, bombarding hostile shores, raiding hostile shipping, and on and on. It holds down the vanquished foe while doing as it pleases on the briny main.

To perform these three functions, says Corbett, fleet designers craft three types of ships: capital ships, “cruisers,” and the “flotilla.” Capital ships serve in the battle line, vying for command of the sea against enemy battle fleets. These are the navy’s brawlers. Cruisers are smaller, more lightly armed, cheaper craft. They’re affordable enough to build in bulk. They, not capital ships, are the true executors of maritime command for Corbett. Cruisers—akin to frigates or corvettes in today’s lingo—fan out in large numbers to police the sea. They safeguard the sea lanes for friendly shipping while barring the sea to antagonists. Flotilla craft are still smaller, cheaper, unarmed or lightly armed vessels that can likewise be built in bulk. They conduct the mundane administrative chores all navies must conduct.

In effect the carrier’s debut as the premier capital ship demoted battleships to secondary status in U.S. naval strategy. Iowas steamed with carrier groups in the Pacific, using their abundant secondary armament to protect flattops against air assault. Battleships resumed their place as capital ships from time to time, but only when the battleground was relatively safe from hostile aircraft. In October 1944, for instance, Admiral Jesse Oldendorf oversaw a surface task force that repulsed a Japanese battleship group making its way through Surigao Strait in the central Philippines. By then, though, gunnery duels had become the exception rather than the rule in naval warfare.

At most battleships—even the vaunted Iowa class—hovered at the fringes of Corbett’s capital-ship contingent.

Technology and tactics, then, had reduced battlewagons to subordinate status—to a fleet auxiliary bearing a hefty price tag. Much like Corbett’s cruisers or flotilla ships, they furnished naval gunfire support and performed other duties after carrier planes had rendered embattled expanses mostly harmless for surface vessels. Their capabilities were wildly excessive for such modest missions—which is why the final two Iowas, Kentucky and Illinois, were canceled along with plans for the future Montana class. Their subsidiary functions in the fleet simply weren’t worth the expense. Lesser craft would do.

A likewise dismal destiny could await the Ford-class aircraft carriers if fleet design is undergoing another phase change. If the CVN is no longer a capital ship in Corbett’s sense—if it no longer spearheads the fight for nautical command—then lawmakers and ordinary citizens may ask why they should bear the expense.

If the march of technology has relegated flattops to auxiliary status, then Corbett’s fleet-design precepts should apply. Top priority should go to capital ships, whatever they may be in the future. Today as always, winning the battle for command is Job One. Meanwhile, the U.S. Navy should acquire smaller, less expensive flattops that can be built in batches to perform support duty. A capital ship may be worth $15 billion if it can sally out to crush the likes of Russia and China in high-seas combat. That’s a tough sell for a fleet auxiliary.

The battleship’s past could be the carrier’s future. Plan accordingly.

James Holmes is J. C. Wylie Chair of Maritime Strategy at the Naval War College and the author of A Brief Guide to Maritime Strategy, released last December. The views voiced here are his alone.

This article is being republished due to reader interest.

Image: Reuters