Here's What You Need To Remember: The most important rule must be this: Tradition should not be a defining principle. Shipbuilders should not retain any features simply because they have always been there; instead, every inch of the design must be carefully examined.

Let the experiments begin, submariners and shipbuilders. Even as shipyards lay keels for a bulked-up “block” of its Virginia-class nuclear-powered attack submarine (SSN), the U.S. Navy espies an entirely new class of attack boat designated SSN(X). The SSN(X) program is slated to debut in 2031, a full twelve years from now. (The program gets underway in earnest in 2034, when the service expects to start buying two boats per year.) That timetable affords the submarine force a bit of leisure to ponder the nature of naval warfare, project the composition of future fleets, and postulate operational concepts and tactics whereby the silent service can navigate an undersea environment in flux.

In short, the experts have time to think about things first rather than vault straight into engineering.

Let’s put that leisure to use. Once submarine officers complete the intellectual legwork they can work alongside naval architects and weapons scientists to devise a sub design that empowers the U.S. Navy fleet as a whole to discharge the missions likely to be entrusted to it. But the design process must not stop with drafting impressive blueprints. The leadership and shipbuilders must treat the fresh design as a hypothesis. A ship design is nothing more than a nifty idea until shipwrights beat the idea into steel and crews take it to sea. Just like in chemistry or physics lab, the team should test their hypothesis in the field, unearth its faults and quirks, refine it, and keep testing until it yields satisfactory results.

Only then should it be pronounced fit for serial production.

That the scientific method should govern naval development sounds self-evident. Evidently, it wasn’t around the turn of the century. Back then a conceit seems to have bewitched the Pentagon leadership. It went something like this: designers could draw up plans for a new platform, engineers could pile on untried weapons, sensors, or other gear, and the platform could go into mass production before proving out in field trials. That’s like a car maker dreaming up a concept car, declaring the prototype ready for sale, and rushing it into production . . . before taking it on the track for a test drive.

Imagine the wreckage to the bottom line of any firm that invented and marketed products the Pentagon way. High-seas operations are the arbiter of what does and doesn’t work in marine technology, just as road testing vindicates a supercar design—or exposes its shortcomings.

The turn-of-the-century procurement philosophy underwent field trials of its own. It gave us littoral combat ships without working sensors and weapon systems but with unworkable crewing and operational schemes; stealth destroyers sporting advanced guns meant to fire ammunition that’s too expensive to buy; and aircraft carriers without operational weapons elevators to arm their warplanes. At best the fin de siècle approach causes delays and costs money as operators discover problems and engineers improvise fixes and retrofit them into vessels already displacing water. At worst, a shipbuilding program could fail altogether—rending a hole in the navy’s fleet design.

Subtract a ship type from the fleet and you risk grave operational or even strategic repercussions. All the more reason to experiment with SSN(X) prototypes long before 2031—and deposit that misbegotten legacy in history’s dustbin.

So much for the jeremiad. The nonpartisan Congressional Budget Office (CBO) has been on a tear at the navy’s expense of late, for instance by issuing an estimate that the SSN(X) will cost $5.5 billion per hull, as opposed to the $3.4 billion forecast in the naval establishment’s long-range shipbuilding plans. The CBO analysts explain that gaping 62 percent discrepancy as an artifact of a disagreement over hull size. Size matters. CBO says it  “assumed” the navy needs a bigger boat to get what it says it wants out of the new class in terms of armament, speed, and other attributes. A vessel boasting the tonnage of the older 9,100-ton Seawolf-class, not the less capacious 7,800-ton Virginia, would be necessary to furnish the internal volume to house these improvements.

Heavier means pricier. QED. Or has it? By all accounts, the Seawolf constitutes the state of the art in SSN technology. But the first boat in the class was commissioned a quarter-century ago, while the design dates to the 1980s. Technology and warfighting concepts have bounded ahead in the interim. Is it really safe to assume that the SSN(X) must necessarily be a Seawolf equivalent—an updated version of a thirty-year-old design?

Maybe, maybe not. Revisiting the fundamentals could help the silent service and the navy leadership answer the CBO’s challenge and vindicate their budgetary outlook. What sort of boat would do so? Rather than gainsay the legendary baseball sage Yogi Berra—who wisecracked that it’s tough to make predictions, especially about the future—let’s stipulate some principles to shape the inquiry shaping the SSN(X). One Principle to rule them all: do not content yourself with improving on existing boats, or even on long-cherished ideas about what a submarine is or how it ought to do business. Situate the new SSN in the strategic and operational context that will greet it when it takes to the depths in the 2030s.

Principle #1—break the mold. 

Over the past couple of years, the Naval War College convened two “Breaking the Mold” workshops aimed at shattering orthodox thinking about all things naval and maritime. I had the privilege of overseeing a cohort of Young Turks who hammered the mold with glee. They rejected measuring naval power by brute numbers of hulls in the water, the traditional gauge of who’s strong and who falls short. Instead, they fell back on a definition of military adequacy beloved of scribes from Clausewitz to Mahan to Corbett: the contender able to concentrate superior combat power at the decisive place and the decisive time is the likeliest victor and, therefore, is adequate unto its purposes.

Nothing in the strategic canon states that it takes a particular type of platform or payload to amass X + 1 units of combat power at a scene of action where the foe fields X units. Doubtless, the “ship” as traditionally understood will remain integral to the panoply of naval warfare. But sea power is undergoing a phase change with the inception of ultra-long-range precision weaponry, unmanned aerial, surface, and subsurface vehicles of many types, land forces able to strike out to sea, and on and on. Submarine warfare is not exempt from this incipient revolution.

Framers of the SSN(X) program should gaze darkly into the future, then, asking themselves whether the “sub” remains the sole bearer of undersea might or they should design the undersea fleet to accommodate new realities. SSNs that operate in concert with unmanned craft could be quite different from the lone wolves that now prowl the oceans and seas.

Principle #2—beware of breaking the mold. 

Now, there’s hidden peril to declaring a longstanding paradigm broken—namely that you might wrongly or prematurely abandon a model that remains valid but needs mending. Philosopher-scientist Thomas Kuhn declares that a “paradigm shift” takes place when so many “anomalies” accumulate—discrepancies the model cannot explain—that the old paradigm’s defenders can no longer explain them away or tweak the model to account for them. The reigning paradigm then collapses, yielding to another that explains reality better.

Plausible enough. But Kuhn implies, without quite saying so, that a twilight zone precedes the paradigm shift. That’s when anomalies have started to appear, but not in such numbers or so compellingly that they refute established orthodoxy beyond doubt. During that ambiguous phase, disputants might toss out a perfectly good paradigm that needs to be refreshed for new circumstances. Witness, for instance, the never-ending debate about whether the day of the aircraft carrier is coming to a close. Anomalies are legion, in the form of saturation missile barrages and the like; whether they’re fatal to carrier aviation remains in question. No naval engagement has put claims and counterclaims to the test—yet. Without a verdict of arms, who’s to say for certain whether these are false anomalies, manageable developments, or bona fide paradigm changers?

Discarding a valid paradigm would court danger just as clinging to an outmoded one would. Worse still, the healthy spirit of breaking the mold could merge with the U.S. Navy’s mostly healthy can-do spirit to produce an unhealthy technophilia—enthusiasm for a new paradigm that may never fulfill its promise. Here’s how that might work. Navy magnates have taken to calling the Trump administration’s proposed 355-ship force “The Navy the Nation Needs,” yet resource constraints appear to rule out more than modest expansion beyond today’s 290 hulls. How should can-do leaders fashion the navy the nation needs without the resources to do it?

Perhaps by indulging in technological fudge factors. Suppose the leadership broke the mold and redefined “the fleet” in terms of combat power rather than raw numbers. Decouple fighting power from numbers of ships and planes and it might be possible to declare that the U.S. Navy boasts 355 ships’ worth of combat power even though it never actually fields 355 ships. Proclaiming that unmanned vehicles and other newfangled gadgetry make up for that sixty-five-ship shortfall would embody the can-do spirit, letting the navy claim to have fulfilled its mandate—potentially without fulfilling it in reality.