Key point: Carriers need to adapt to changing threats and technology if they are to stay deadly and survivable.

How can the U.S. Navy prolong the relevance of its big-deck aircraft carriers amid increasingly menacing surroundings? In part, through hindsight. The Japanese raid on Pearl Harbor rudely evicted dreadnought battleships from their perch atop the navy's pecking order. The day of the aircraft carrier had arrived. And yet battleships found new life for a time, pressed into service for secondary but vital functions. That could be the flattop's eventual fate as well. Naval-aviation proponents may find insights from battleship history discomfiting. They should study them nonetheless.

Amphibious operations, not sea fights against enemy surface fleets, gave battleships renewed purpose after Pearl Harbor. Dreadnoughts took station off the Solomon Islands scant months later, pummeling Japanese Army positions to support U.S. Marines embattled on Guadalcanal. The opposed landing is among the most grueling missions amphibian forces can undertake. Debarking from amphibious transports, making the transit from ship to shore in fragile landing craft, and clawing their way onto the beach under fire constitute the most delicate part of the endeavor.

Carl von Clausewitz pronounces defense the stronger form of war. Never is this more true than in amphibious combat. Defenders strew obstacles along the beaches, position gun emplacements to rake landing craft approaching through the surf and make things hellish while soldiers and marines are at their most vulnerable. Nor is island warfare any cakewalk, even after the force is ashore. Softening entrenched enemy defenses, then, is imperative both before sea-to-shore movement commences and after the fighting moves inland.

Battlewagons rendered yeoman service as shore-bombardment platforms throughout World War II. Reactivated Iowa-class battleships, moreover, saw action during the Korean War, the Vietnam War and the first Gulf War. Nor is this purely an Asian enterprise. Indeed, this Friday marks seventy years since swarms of Allied ships descended on the French coast. Troops stormed the Normandy beaches in history's most epic opposed landing. Some 10,800 Allied combat aircraft dominated the skies, flying from airfields in nearby Britain. Battlewagons, cruisers, and destroyers cruising offshore rained gunfire on German strongpoints.

To deadly effect. Battleship gun rounds are comparable in weight to a Volkswagen Bug. Imagine flying economy cars exploding in your midst and you get the idea. So lethal was Allied naval gunfire that Desert Fox Erwin Rommel informed his Führer that "no operation of any kind is possible in the area commanded by this rapid-fire artillery." Quite a testament coming from one of history's great commanders.

And yet furnishing fire support was quite a comedown in status for the battlewagon, once the pride of navies from London to Washington to Tokyo. Seafarers reared on the works of Alfred Thayer Mahan and Sir Julian Corbett assumed fleets of "capital ships"—battleships escorted by their lighter, but still-heavily-gunned, thickly armored brethren—would duel for maritime supremacy at the outbreak of war. By sinking or incapacitating an enemy battle fleet, the navy would secure the blessings of "command of the sea." That meant virtually unfettered freedom to blockade enemy shores, assail enemy merchantmen, or project power ashore.

The battleship once performed the glitziest of missions, but Pearl Harbor demoted it to secondary, unglamorous duty. Ships built to withstand hits from exploding VWs could venture within reach of shore-based enemy defenses—artillery, tactical aircraft, and the like—with good prospects of survival. And commanders could risk them with impunity. If the aircraft carrier was now the centerpiece of naval warfare, it was imperative to conserve flattops for future actions. After December 7, by contrast, the dreadnought was a wasting asset searching for a mission.

So why not send these vessels into harm's way? Once dethroned from the battle line, in short, battleships became expendable assets. In so doing they became ground-pounders' favorite ships. Therein lies wisdom. Herewith, are five lessons from the battleships' twilight years, applied to today's high-tech, access-denial/area-denial age:

Extend striking reach: As noted before, modernized battleships saw action in Korea, Vietnam and the Persian Gulf. But these were relatively permissive surroundings where few defenders could do serious damage to armored vessels. More forbidding settings might have told another story. To be sure, battleship guns boasted extravagant range by gunnery standards. They could send rounds over twenty miles downrange. But that's short range for today's speedy attack aircraft and antiship missiles. Closing in on enemy coastlines, perversely, compresses the time available to ward off attack. That would render a battleship's staying power doubtful despite its ability to take a punch. Boosting the range of a ship's main armament, it seems, is critical to survival in this age of gee-whiz antiship weaponry. The farther away from enemy countermeasures, the better a man-of-war's prospects for staying alive—and accomplishing its goals.

Boost shipboard defenses: On the other hand, the laws of physics are a stern taskmaster. Battleships could disgorge one or two rounds per minute from each of their nine big guns. Hence, their devastating impact on defenders at Normandy. But the rate and volume of fire may suffer as the range separating the firing platform from its targets increases. Long range also reduces the amount of territory a vessel can reach. These problems are acute for a carrier, which reuses the delivery systems—the aircraft—that put ordnance on target. Aircraft have to launch, make their way to the combat zone, turn loose their weapons and make it back to the ship to refuel and rearm. That cycle takes time—and the farther offshore the flattop, the longer it takes. The strike group, thus, needs to get as close to its objectives as possible. Consequently, anything ship designers can do to harden ships against air and missile attack will improve the carrier's, and its escorts', ability to stand into danger at acceptable risk. Rugged construction, stealth, exotic weaponry, such as lasers and electromagnetic railguns—any of these will enhance warships' capacity to withstand landward assault and project power. Suffice it to say, striking the balance between self-protection and offensive firepower is a dicey prospect.

Don't cling too tight to the old: Seamen have a habit of falling in love with ships, ship types, and missions. Letting go is hard to do—even when circumstances warrant. Mahan defined capital ship broadly, to mean any warship capable of meting out and taking heavy blows. Naval commentators, nonetheless, construed his writings as advocacy on behalf of a specific ship type—the armored battleship. Once that assumption found its way into U.S. Navy strategy and doctrine, it took incontrovertible evidence—such as Japan's air assault at Pearl Harbor—to shatter habitual ways of thinking about sea combat. Better to remain intellectually and doctrinally nimble and repurpose old ships, aircraft and armaments when need be. Remember Rommel's verdict on naval gunfire at D-Day. Naval gunfire exuded little sex appeal. But it was a decisive factor in France.

Embrace the new: The reciprocal is that navies tend to see new, experimental ships as fleet auxiliaries—as assets that help the existing fleet execute what it already does, only better. Early on, for instance, naval officers considered the submarine an adjunct to the battle fleet. Aircraft carriers and their air wings were "the eyes of the fleet," scouting and screening for battleships, rather than offensive weapons in their own right. The dreadnought thus lingered on long after its successor, the flattop, hove into view. (Today the U.S. Navy may be repeating the pattern with unmanned-aircraft development. Having debated whether UAVs should emphasize ground attack or surveillance, navy potentates evidently favor the latter. A new set of eyes for the aircraft-carrier strike group may be in the offing.) Hanging onto old hardware and doctrine can represent a grievous mistake—so can being standoffish toward novel warmaking methods.

Find an alternative: It is entirely possible that the technical challenges cataloged here are insoluble at any affordable cost, much as restoring the dreadnought's supremacy was impossible in World War II. Accordingly, it behooves the U.S. Navy and friendly services to experiment with new technologies and concepts now, in case the sunset of the aircraft carrier approaches. We make much of the abrupt switch between battleships and carriers as the capital ships of choice. But navy leaders didn't conjure the carrier into being in 1941, when they needed a new capital ship. Rather, farsighted leaders such as Admiral William Moffett—a battleship-officer-turned-air-power-enthusiast—had pushed the development of naval air during the era of battleship supremacy. Hence, the implements to prosecute an aviation-centric strategy already existed when the navy needed them. Commanders merely had to divine how to use them. As things worked out, the ex-capital ship performed support duty while its replacement bore the brunt of navy-on-navy fighting. Not a bad division of labor.

In short, battleship history suggests that today's leaders face an array of technical, tactical and operational challenges. It also suggests that imagination poses the stiffest challenge. One hopes there's a William Moffett out there thinking ahead to the next big thing.

James Holmes is Professor of Strategy at the Naval War College and coauthor of Red Star over the Pacific, just out in Mandarin from the Chinese Academy of Social Sciences. He was the last gunnery officer to fire battleship guns in anger, in 1991. The views voiced here are his alone. This first appeared in June 2014.

Image: DVIDShub.