The proliferation of land-based missiles, cheap drones, and integrated anti-access/area-denial networks has overturned centuries of assumptions about naval dominance, allowing regional powers—and their proxies—to hold critical maritime trade at risk. Traditional sea powers must adapt on two fronts: preventing chokepoint closures through deterrence by denial and mitigating them through resilience by design.

The global economy floats. More than 80 percent of world trade by volume, and over 70 percent by value, moves by sea. Nothing else comes close for bulk commodities—oil, liquefied natural gas, grain, iron ore—and nothing will anytime soon. But the sea lanes that carry that commerce are not evenly distributed. They funnel through a handful of narrow passages: Hormuz, Malacca, Bab el-Mandeb and Suez, the Turkish Straits, Panama. Whoever can close one of those doors, even briefly, holds a lever on the world economy.

For most of history, that lever belonged to navies. The young American republic sent its first frigates to the Barbary Coast because merchant hulls were being seized and crews ransomed—commerce protection was the U.S. Navy’s founding mission. During the Civil War, the Union’s blockade strangled Confederate cotton exports—cutting them by an estimated 95 percent—and starved the South of arms and matériel. The Royal Navy’s distant blockade of Imperial Germany did much the same to the Kaiser’s wartime economy a half-century later. And in two World Wars, Allied convoys fought German U-boats and surface raiders across the Atlantic to keep Britain fed and armed. The lesson of all of it seemed settled: control of the sea meant control of seaborne trade, and control of the sea belonged to whoever put the strongest fleet on it.

That balance has shifted. Lord Nelson is often credited with the observation that “a ship’s a fool to fight a fort,” and for two centuries the aphorism described a tactical problem you could sail around. No longer. Today’s “fort” is a reconnaissance-strike complex: precision-guided ballistic and cruise missiles, swarming drones costing a few thousand dollars apiece, sea mines, over-the-horizon sensors, and the networks........

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