Here's What You Need to Remember: If a coastal state like China or Russia asserts outsized claims to jurisdiction over offshore waters and no one challenges those claims, its claims—even though unlawful—have a way of calcifying into international custom over time.

The question is a hardy perennial among those who hold forth about maritime strategy in Asia: are “freedom of navigation” operations enough? Are periodic cruises through waters where a coastal state claims rights and prerogatives beyond those codified by treaty enough to safeguard maritime freedom?

Answer: freedom-of-navigation operations are necessary but not sufficient guarantors of “freedom of the sea,” the nearly limitless liberty to use the sea for mercantile and military pursuits, and of the liberal system of seagoing trade and commerce it underwrites.

Freedom-of-navigation operations are necessary for legal reasons. As retired Royal Navy admiral Chris Parry likes to say, navigational freedoms are something like the “right of way” in English common law. They endure as long as seafarers use them. The right of way permits citizens to traipse across private property along certain pathways provided people actually exercise that right. If no one does, the right of way has a way of lapsing over time. Ownership reverts to the land’s holder in full.

Use it or lose it.

Similarly, if a coastal state like China or Russia asserts outsized claims to jurisdiction over offshore waters and no one challenges those claims, its claims—even though unlawful—have a way of calcifying into international custom over time. International law is a system of customary law as much as it is a system of written treaties and agreements. If navies and merchant fleets fail to exercise their rights under the law of the sea to their fullest, compliance with the coastal state’s demands could begin to look like consent to those demands. Acquiescence could become the reigning custom—and if so freedom of the sea will have been abridged in the waters at issue.

Hence the necessity to defy extralegal claims early and often.

Freedom-of-navigation cruises are insufficient for military and diplomatic reasons. These are come-and-go operations whereas a broad swathe of the seafaring world should go to contested waters and stay in order to make a statement that resonates regarding freedom of the sea.

Think about it. What does an American warship accomplish when it passes by a Chinese-held rock in the South China Sea—in 2016 an international tribunal ruled that none of the Spratly or Paracel islands qualifies as an island in a legal sense—and leaves? It exercises the right of way codified by the law of the sea. That’s good.

But in all likelihood a Chinese warship will have shadowed it, will have instructed it to leave, and may have harassed it during its transit. The fact that U.S. Navy vessels do come and go lends credence to a diplomatic narrative issuing from Beijing. The tale goes something like this: Americans broke into our territorial waters and we chased them off. Chinese spokesmen essay a sort of diplomatic alchemy. They try to portray demonstrating on behalf of freedom of the sea into cutting and running from an embattled zone. If a critical mass of influential audiences buys the Chinese line, it becomes reality in their minds until and unless debunked.

How to deflate China’s narrative? Rather than put in the occasional fleeting appearance, friends of navigational freedom should show up in disputed waters such as the South China Sea, and they should stay. Constancy should be their watchword.

Fortunately, Washington and likeminded capitals seem to have alighted on such a strategy. U.S. Pacific Command boss Admiral Phil Davidson recently told the Senate Armed Services Committee that allies will join future freedom-of-navigation deployments. The more flags fly in contested expanses the better.

That’s why recent news out of allied capitals is so heartening. For instance, Tokyo dispatched one of its “helicopter destroyers,” or light aircraft carriers—the pride of the Japan Maritime Self-Defense Force—to operate alongside U.S. Navy units in the South China Sea. In so doing Japan’s political leadership stated that it will not buckle under Chinese pressure anywhere around the Asian rim.

Europeans have gotten into the act. London dispatched a Royal Navy amphibious transport to the region last fall to put in appearance near Chinese rocks, and last month a Royal Navy frigate joined U.S. Navy ships in Southeast Asia for several days of combined operations. Great Britain even intends to open a military base in the South China Sea—punctuating its return to seaways “east of Suez” decades after decolonization. A base would anchor the British and allied presence in the region—helping naval forces go there and remain.

European aircraft carriers will soon join the mix. Paris has announced that the nuclear-powered flattop Charles de Gaulle, fresh from its midlife overhaul, will journey to the South China Sea this year. Britain’s first supercarrier, Queen Elizabeth, will follow this year or next—and a U.S. Marine Corps squadron flying F-35 stealth fighters will join her air arm. London has bruited about the idea of creating an Anglo-French carrier force—helping Europeans maintain a constant and formidable presence in waters claimed by China. Paris isn’t quite there yet, politically speaking, but even talking about pooling naval resources constitutes progress.

And if the allies sustain their on-scene naval presence for a long time? Beijing will find it increasingly tough to convince others its navy has chased off ships that never leave. Its parable of Chinese power and allied weakness will no longer pass the giggle test.

Turn to strategic theory in closing. Admiral J. C. Wylie describes control of somewhere or something as the purpose of military strategy, and he depicts the “man on the scene with a gun”—the soldier—as the final arbiter of control. The soldier appears on the scene and stays, outgunning local resistance. He embodies control of dry land. He is control, says Wylie.

Teleporting Wylie’s logic seaward, naval forces on the scene that boast serious firepower are the saltwater counterparts to the soldier. If they mount a standing presence, forces flying not just American but Asian and European flags can belie China’s efforts to impose control as well as its self-boosterism. Its creeping encroachment on freedom of the sea could stall as the seafaring world rallies.

Is success in this armed conversation a foregone conclusion? Hardly. The outcome of strategic competition never is. But an enduring, multinational show of power and resolve might prove sufficient to curb the China challenge.

James Holmes is J. C. Wylie Chair of Maritime Strategy at the Naval War College. The views voiced here are his alone.

Image: Reuters