Here's What You Need to Remember: Corralling Chinese quarry within the island chain would help Taipei safeguard the island’s east coast. And it would let the Taiwanese armed forces shore up the central segment of the “Great Wall in reverse” the U.S. armed forces seem intent on erecting along the island chain, in concert with allies, to constrain PLA maritime movement.

New submarines for Taiwan? Yes, please!

Submarine construction is poised to become a reality now that Washington has lifted restrictions that once prohibited exports of equipment to outfit or arm Taiwanese boats. It appears indigenous builders will construct the hulls—eight is the number bruited about—while foreign partners will supply the sensors, combat systems, and weapons along with technical advice.

A vibrant undersea fleet would pay political and strategic dividends that the current contingent of two aging and two positively elderly boats could never yield.

It only makes sense for Taiwan to take charge of its own destiny. The gods of world affairs help those who help themselves. Wise societies tend to their own security and interests to the utmost extent possible rather than trust to foreign allies who could prove untrustworthy in times of martial strife.

Human nature helps explain why self-help represents the bedrock underlying international relations. General George S. Patton, a keen observer of the human condition, opined that people cheer likely victors while scorning likely losers. And so they do. Who flocks to a losing cause? Few. People either side with winners, or they side with outmatched contenders who do their darnedest in their own cause—in other words, with pugilists who could succumb yet command admiration and could prevail with help.

Winston Churchill’s Great Britain showed pluck when it stood alone against the Axis in 1940-1941. It was a worthy cause. Submariners could be Taiwan’s answer to Royal Air Force pilots who dueled the Luftwaffe daily during the Battle of Britain. Taiwan Navy (or Republic of China Navy, ROCN) boats could ward off attacks on the homeland or strike offensively while inspiring allies to rally to the cause.

Military sage Carl von Clausewitz explains allies’ halfheartedness in terms of competing priorities. One combatant may support another, and do so sincerely. But it never takes its ally’s cause as seriously as it takes its own. Tepidly committed, it devotes modest diplomatic, economic, and military resources to common endeavors; it writes off an endeavor when costs and dangers mount.

When the going gets tough, confides Clausewitz, less-than-tough allies get going—toward the exit. Inhabitants of Taiwan understand this phenomenon better than most. The prospect of abandonment stares islanders in the face every day as China deploys diplomatic, economic, and military inducements or coercion to discourage outsiders from coming to the island’s defense.

Which is why Taipei must seize ownership of its defense against Big Brother across the Taiwan Strait. At sea that means shifting from a “sea-control” to a “sea-denial” strategy. Sea control is a strategy of the strong. A navy intent on sea control strives to sweep the antagonist from important waters and make them a preserve from which to control the sea lanes or project power ashore.

Once upon a time the Taiwan Navy aspired to rule the waves, and it stood a reasonable chance of doing so. Material and human excellence made it a legitimate contender against the large but backward People’s Liberation Army Navy (PLA Navy), its archnemesis. Those days have receded into memory as China’s military mass-produces high-tech fighting ships and planes, takes to the sea and sky, and backs its battle fleet with shore-based firepower.

In short, Taiwan’s navy no longer commands nearby waters and stands little chance of regaining maritime supremacy. That doesn’t mean all is lost. To protect their island ROCN mariners mainly need to deny the PLA Navy control of waters adjacent to Taiwan, not dominate those waters for themselves. If they can fend off amphibious assault, break blockades, and assail shipping, they can grant allies—chiefly the United States—time to fight their way into the theater and reverse Chinese aggression.

Sea denial is a time-honored strategy of the lesser contender. Handled deftly and imaginatively, swarms of inexpensive yet superempowered small craft can give a hostile fleet a very bad day. As historian Theodore Ropp observed of the fin de siècle French Navy, David need not defeat Goliath—the Goliath of those days being Great Britain’s Royal Navy—to curtail the giant’s freedom of movement near shore.

If anything Ropp’s logic of sea denial is even more compelling today than it was during that age of rudimentary steamships, diesel submarines, and torpedoes. Today diesel submarines fitted with “air-independent propulsion” can vanish into the depths for long stretches to elude detection. Fast patrol craft can mingle with surface traffic or lurk along congested shorelines for concealment.

Sea-denial platforms riding the waves or prowling beneath can launch torpedo attacks or loft anti-ship missiles against oncoming aggressors—and they can cruise in company with unmanned aerial, surface, and underwater vehicles of all types. Their attacks would be hard for PLA Navy shipping to counter in the cramped quarters of the Taiwan Strait, where engagements happen at short range and defenders have scant time to react.

David has options.

Even a single boat can throw an opponent’s strategy askew in modern naval warfare, as both the Argentine and British navies learned during the Falklands War of 1982. A Royal Navy nuclear-powered attack sub sank the cruiser General Belgrano, pride of the Argentine Navy. But the Royal Navy task force expended virtually Britain’s entire war stock of anti-submarine munitions in a futile effort to sink an Argentine diesel boat stalking the fleet.

One imagines the Taiwan Navy would easily outperform the Argentine Navy—especially if it were a beneficiary of U.S. and allied hardware, methods, and counsel. The prospect of effective ROCN subsurface operations could distort PLA Navy operating patterns to Taiwan’s benefit. In the ideal case it could deter entry into the island’s near seas altogether.

Mass—numbers of vessels—appears adequate unto Taipei’s purposes. The inventory will presumably stabilize at eight boats once new craft are built and decrepit ones retire. Factor in training, upkeep, and deep maintenance, and three or four should be underway or ready to put to sea for combat duty at any given moment. These are strategic assets. Naval commanders should keep boats on patrol at all times, honing crews’ tactical proficiency while guarding against a preemptive strike on the sub force at its moorings.

Beyond that, how can the Taiwan Navy maximize its potential for sea denial? Sea denial is strategically defensive in outlook, but that doesn’t rule out offensive tactics. In fact, offense is the beating heart of strategic defense according to the masters of maritime strategy. Sure, ROCN subs could take a passive stance, in effect standing sentry duty off seaports such as Kaohsiung or beaches likely to be targeted during a cross-strait amphibious assault. They could await attack and strike back hard. This would be valuable service.

Better yet, skippers could take an offensively minded, enterprising stance. Taiwan Navy boats could lurk off mainland seaports to raid shipping as it enters or leaves harbor. Or they could loiter in or around straits that pierce the first island chain. Barring the Luzon Strait—PLA Navy boats’ favorite passageway between the Western Pacific and South China Sea—would constitute an immense contribution. The wide Miyako Strait, to Taiwan’s north, could offer rich hunting grounds as well.

Corralling Chinese quarry within the island chain would help Taipei safeguard the island’s east coast. And it would let the Taiwanese armed forces shore up the central segment of the “Great Wall in reverse” the U.S. armed forces seem intent on erecting along the island chain, in concert with allies, to constrain PLA maritime movement.

Here’s where the political dividends come in. Not only would ROCN efforts advance Taiwan’s strategic fortunes, they would advance allied strategy as a whole. In turn they would generate a powerful incentive for allies such as the U.S. Navy and Japan Self-Defense Forces to bear a hand in Taiwan’s defense. Reciprocity—not just vague pledges to render assistance—would unite the allies behind a common cause. Taipei would help others by helping itself, and self-interest would prompt others to help Taipei.

A virtuous cycle would have been set in motion.

So by all means let indigenous shipyards construct the hulls, and let foreign partners supply such help as shipwrights and submariners need. The more boats take to the sea and the faster they get there, the better. In the meantime, it’s never too early to start holding quiet discussions among the silent services about common tactics, training, methods for waterspace management, and on and on.

Put the human factor in order now and you reduce the problem of bolstering Taiwan’s undersea prowess to a matter of acquiring new widgets. Let’s refine the art and science of multinational combat beneath the sea. And let’s start forthwith.

James Holmes is J. C. Wylie Chair of Maritime Strategy at the Naval War College, coauthor of Red Star over the Pacific, and author of A Brief Guide to Maritime Strategy. The views voiced here are his alone.