The end of Pax Americana at sea

The Ukrainians have a lot to teach the United States and the Trump administration about naval warfare.

When Russia invaded four years ago, Ukraine was without a navy that could plausibly contest control of the Black Sea, and the Russian military was able to threaten it with amphibious landings behind its lines. Today, Ukraine’s fleet dominates the Black Sea and is almost entirely autonomous (unmanned). In four years, Ukraine has driven the Russian Black Sea Fleet from Sevastopol, sunk roughly a dozen warships, crippled the same number, and broken Russian command of this strategically vital body of water.

Elsewhere, a Russian liquid- natural- gas (LNG) carrier, the Arctic Metagaz , was hit near Malta in March by Ukrainian unmanned surface vehicles controlled from Libya. The ship then spent two months as a floating burnt wreck, drifting through Italian and Maltese waters, before recently being secured off the Libyan coast.

All of this was achieved on a shoestring budget, without the need to build or man a conventional crewed Navy. Meanwhile, in order to close the Strait of Hormuz and restrict Iranian shipping, Team Trump puts multibillion-dollar US Navy vessels at risk. Using these ships and crews to reopen the strait to American and allied shipping remains too potentially costly, and so Hormuz remains closed except for the few commercial ships daring enough to run the blockades.

Chaos on the seas is rising, and unmanned naval warfare is transforming everything we thought we knew about maritime military strategy. Global shipping and global geopolitics are already being affected. How America adapts — or fails to adapt — to this technological threat will have implications for years to come.

Learning from the West’s Ukrainian allies is essential.

The pace of change has been extremely rapid. In 2022, Ukraine’s unmanned surface vehicles, or USVs, were single-use, ran fewer than 200 miles, and had very limited autonomy. The 2025 generation is much more capable: Ukraine’s Sea Baby drone can run almost 1,000 miles at nearly 50 knots on satellite comms (using satellite guidance) and carries up to two tons of payload, which can be rockets, guns, sensors, or explosives. The Ukrainian ministry of defense is beginning to operate such drones in coordinated swarms and has integrated autonomous targeting, allowing operations in communications-denied environments. The ministry’s Magura V7 USV has even used missiles to shoot down two Russian Su-30 fighter jets.

The central innovation is the USV. Unmanned naval surface weapons have a long history, from fireships , employed as early as the siege of Tyre in 332 BC, to Israeli inventions in the modern era. In 1948, Israel sunk the Emir Farouk , the flagship vessel of the Egyptian navy, by piloting small speedboats loaded with explosives into the hull, with the operators jumping out at the last minute. But the ability for modern USVs to operate autonomously, over thousands of miles of range, is new and revolutionary.

Throughout history, denying sea access to an enemy required one of two things: either a chokepoint, with mines or coastal batteries, which allowed a land power to dominate a small area of sea; or a blue-water navy, recently including submarines. This is why great naval powers have secured island fortresses near critical straits, in order to project power in the places where other powers might contest freedom of navigation: Singapore, Gibraltar, and Penang in Malaysia, for example.

Furthermore, as Alfred Thayer Mahan, the great American naval strategist, pointed out, a navy rests on a merchant service (commercial shipping traffic) and the maritime commercial society that supports both. Historically, it has been the case that without a commercial maritime society, a country’s claim to projecting power at sea was tenuous at best. Germany, for instance, tried to project sea power in both world wars, leveraging submarines, and failed both times. France tried during the Napoleonic Wars, and was largely unsuccessful. Examples of this abound.

With autonomous drones, maritime power projection no longer requires a chokepoint or a navy. Sea denial is now open to non-maritime powers, which will have serious commercial as well as military implications, thus undermining Mahan’s second condition for naval dominance. This is the most fundamental change in sea power strategy in centuries.

America’s current strategy of relying on aerial drones and cruise missiles can certainly sink ships, but effective anti-ship missiles are expensive and hard to build: a Naval Strike Missile, or NSM,  is very capable and has stealth capabilities but costs about $2 million per missile, and delivers a 500-plus-pound payload with perhaps 180 miles of range. A new Tomahawk missile costs around $3 million, carries a heavier payload, and has a longer (1,500-mile) range but requires a large ship with vertical tubes for launch and lacks some of the stealth features of the NSM. By contrast,…