The rising oceans of the 2040s will be battlefields for both crewed ships and robotic ones. In a document called Force Design 2045, the US Navy’s strategy guiding the next decades of ship and vehicle development, anticipating what war will be like in the middle of the century is crucial to ensuring peace or, failing that, seizing victory. In announcing the strategy, Chief of Naval Operations Admiral Mike Gilday wrote that “the world is entering a new age of warfare, one in which the integration of technology, concepts, partners, and systems—more than fleet size alone—will determine victory in conflict.”

The strategy is couched, first and foremost, in continued open, free, and lawful trade across the seas, including the familiar commerce of goods and materials, but also incorporating the undersea cables that connect the internet as vital infrastructure. To ensure this peace, the plan says the Navy must maintain a nuclear deterrent (presently missile-carrying submarines), control the sea to deter invasion (and land Marines as needed), and to defeat enemies in ocean battles should it come to that.

To meet this need, the Navy plans to maintain its crewed fleet of aircraft carriers, nuclear-armed ballistic submarines, nuclear-powered attack submarines, as well as crewed destroyers and frigates. The Navy also plans to introduce over a hundred robotic ships. Here’s how it’s all going to shake out.

How many ships?

Variations of this strategy have existed since the dawn of nuclear-armed submarines. Beyond submarines, the question for the Navy has been how it meets those objectives, and what composition of ships it needs to get there. In the latest strategy, the Navy offers clear numbers.

“In the 2040s and beyond,” reads the strategy, “we envision this hybrid fleet to require more than 350 manned ships, about 150 large unmanned surface and subsurface platforms, and approximately 3,000 aircraft.”

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The exact number of ships needed by the Navy has been the subject of presidential campaigns, with then-candidate Trump proposing a 350-ship Navy when running in 2016. In October 2020, then-Secretary of Defense Mark Esper called for a Navy with more than 500 ships. At present, the US Navy has 298 ships, with previous plans floated this year suggesting the Navy aim for a goal between 316 and 367 ships.

With the new strategy, the Navy sets an ambitious goal for 52 more crewed vessels than at present, while also showcasing that to get the reach and numbers promised by a 500-ship fleet, the Navy will have to lean heavily on uncrewed ships, like those tested this month at the major RIMPAC naval exercises.

So what will the drone ships do?

The most immediate use for uncrewed ships and robotic submarines will be as scouts. The ocean is vast, and scanning the seas in real time allows the Navy to see some of it and plan accordingly.

“The integration of autonomous USVs with manned combatants will give fleet commanders much-needed enhancements to maritime domain awareness, thereby increasing decision speed and lethality in surface warfare,” Captain Scot Searles, Navy program manager for unmanned maritime systems, said in a release describing the use of uncrewed ships at RIMPAC.

Sensors on robotic ships represent an ideal initial use case, because that approach offers an immediate benefit without requiring constant human supervision or careful monitoring. These roles are also good testing opportunities for autonomous navigation and remote direction, both features that will be crucial should oceans become battlefields.

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“Unmanned surface and subsurface platforms to increase the fleet’s capacity for distribution; expand our intelligence, surveillance, and reconnaissance advantage; add depth to our missile magazines; supplement logistics; and enhance fleet survivability,” reads the strategy. “This transition will rebalance the fleet away from exquisite, manpower-intensive platforms toward smaller, less-expensive, yet lethal ones.”

Scouting will likely be the first mission for these ships, but future missions will include resupply and transport, allowing extra ammunition and other vital cargo to be carried on ships without sailors. To get to “lethal,” these uncrewed ships will need to have weapons, as the Navy has already demonstrated

Under remote operation, a missile battery on an uncrewed ship could still be under human control, with the decision to fire handled by humans who are located on a different vessel. As with any autonomous sensor-and-weapon system, the possibility exists that targeting and firing could be made autonomous in the future, though nothing in the strategy indicates that as an approach.

Armed uncrewed ships, like the planned Large Unmanned Surface Vehicles, will carry vertical launch system missile tubes, expanding the number of missiles that can be brought to battle. Uncrewed armed ships can’t do everything a crewed missile-destroyer can, like relief missions or dissuading attacks of opportunity. In a ship-to-ship naval battle, the available number of missiles ready to launch may be more important for victory than the number of ships in a flotilla.

In addition to the uncrewed ships, the strategy says the Navy will “augment the force with an evolving complement of thousands of small, rapidly adaptable, and attritable unmanned platforms.” These many small and expendable drones in land, surface, and underwater will include models that scout ahead of ships, ones that wait in the ocean a long time, and ones that can hurt enemy vessels, through electronic warfare or explosive power, all with the goal of enhancing the fighting ability of the crewed fleet.

Putting it all together

As the Navy plots a strategy for a course between now and the 2040s, it is focused primarily on a singular potential threat: the growing naval capabilities of China. Where once Russian and before that Soviet navies were the focus of US fears, China has overtaken the country in the imagination and warplanning of the Pentagon. Fighting a future war against China, should it occur without a world-ending nuclear exchange, means adapting to a very different reality, a kind of naval warfare that has not yet been attempted.

In the decades since the Pacific campaigns of WWII, missile technology has improved tremendously, not to mention the development of modern hypersonic weapons. Missiles shift the calculus for fleets, as a successful missile hit can sink a massive and expensive ship for a fraction of what it cost to produce the vessel. Replacing a ship takes years even in ideal conditions, and even if a ship is damaged, it can still be out of commission for months.

While the Navy’s plan still relies on aircraft carriers, submarines with nuclear missiles and those without, and big crewed escort ships, adding in uncrewed vessels means the burden of resupply can gradually be removed from crewed ships, preserving sailors for the vessels on which they’re most needed. The ability to scale up ship operations, without training new human crews, means the Navy could operate more and smaller resupply vessels, minimizing the harm from each loss. 

While the Navy sets out a strategy for 2045, the immediate impact will be seen in spending, on what ships and programs the Pentagon decides to build out for its fleet now. If the future of war is human-crewed fighting ships with uncrewed resupply and robotic scouts, that future will start to take shape in shipyards.