U.S. Submarines: Run Silent, Run Deep...On Diesel Engines?

"Now may be the time to break up the nuclear monopoly."

"Underway on nuclear power", radioed the skipper of USS Nautilus in 1955, after taking history's first nuclear-powered attack submarine to sea for the first time. Nautilus's maiden cruise left an indelible imprint on the navy. Her success, cheered on by the likes of Admiral Hyman Rickover, the godfather of naval nuclear propulsion, helped encode the supremacy of atomic power in the submarine force's cultural DNA.

Things were never the same after that. America built its last diesel-electric sub, once the state of the art, not long after Nautilus took to the sea. Not since 1990 has the U.S. Navy operated conventionally powered boats. It's been longer than that since they were frontline fighting ships. For a quarter-century, then, it's been all nukes, all the time. No U.S. shipbuilder even constructs diesel boats nowadays.

That was then. Now may be the time to break up the nuclear monopoly. To wit, imagine permanently forward-deploying a squadron of diesel attack boats, or SSKs, to likely hotspots. Such a force would expand America's silent service, reversing the ongoing slide in numbers of hulls. It would do so at reasonable cost in this age of budgetary stress. A standing East Asia squadron would be close to the action. Likely based in Japan and Guam, it would amplify the U.S.-Japanese fleet's prowess vis-á-vis China's navy and merchant marine. It would empower Washington and Tokyo to deny China access to offshore waters without committing the whole fleet of U.S. nuclear-powered boats to the endeavor. And in the process it would open up new vistas for building and reinforcing alliances.

Greater numbers, middling cost, a heavier punch in battle. That's a major contribution from such humble craft. U.S. submariners' diesel-propelled past could be, and should be, part of their future.

There's nothing new or especially radical about conventional U.S. subs' prowling the Western Pacific deep. They did so to devastating effect during World War II. For instance, the Philippine Islands was home to the largest concentration of U.S. submarines in the Pacific on the eve of hostilities. U.S. commanders squandered a golden opportunity to run wild against transports carrying Japanese troops to invade the Philippines. But their missed opportunity doesn't detract from subs' potential to confound opponents amid Asia's intricate nautical terrain. It's an exception that proves the rule.

And indeed, American submarines vindicated their potential in ensuing years. U.S. Pacific Fleet boats were among the first vessels to return to Asia following the Japanese raid on Pearl Harbor. Ordered to sea while the battle line was still ablaze at Ford Island, they helped dismember an island empire. Empires like Japan's depend on ships to ferry all manner of warmaking materiel—raw materials, foodstuffs, finished goods—hither and yon. Take away seaborne movement and you cut the lineaments binding the imperial enterprise together.

The submarine campaign grew more and more effective as the U.S. offensives undulated across the Central and South Pacific. U.S. Navy, Marine and Army amphibious forces wrested outer islands from Japan, letting the navy position, maintenance and logistics outposts closer to the foe. Submarine tenders—floating repair and supply depots for all intents and purposes—staged support operations westward of Hawaii. As the transpacific campaigns progressed, boats wasted less time transiting to and from assigned hunting grounds. They spent more time strewing the seafloor with enemy merchantmen and men-of-war.

Forward bases, then, offset the tyranny of distance—allowing the submarine force to mount a stifling presence in Asian waters. Wartime prime minister General Hideki Tōjō catalogued submarine warfare among three critical determinants of Japan's defeat—high praise from someone in a position to know.

And afterward? Ravaged by undersea combat during World War II, Japan built an impressive submarine force of its own to help prosecute the Cold War. Japan Maritime Self-Defense Force (JMSDF) diesel boats turned geography to advantage, lurking in and around the straits that pierce Asia's offshore island chains. Crews monitored and encumbered east-west movement between the China seas and the Western Pacific. Soviet skippers often balked at attempting the passage. The JMSDF, in short, forged itself into a lethal weapon for a cold war beneath the waves.

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