Like a Christmas wish list, the Navy wants a fleet of 355 ships.

It just can’t afford it.

“Will we get to 355 ships?” asked Admiral Robert Burke, the Navy’s Vice Chief of Naval Operations, at a recent conference. “I think with today’s fiscal situation, where the Navy’s top line is right now, we can keep around 305 to 310 ships whole, properly manned, properly maintained, properly equipped, and properly ready.”

The $205.6 billion for Fiscal Year 2020 that the Navy has requested – bigger than the economies of the majority of nations on Earth – would seem to be plenty. But even if Congress approves that amount, it would only bring the Navy’s battle force of warships and support vessels to 314 by 2024. That’s more than the current 280-strong force, but only about four-fifths of the 355-ship goal by 2047.

Burke’s conclusion was logical: more money equals more ships. “If our top line does not go up, if it remains where it is now and is projected to remain in the future defense plans, that’s about where we can get to and do it right, in terms of man those ships and maintain them and have all the ordnance for them and generate readiness,” he said. “We would need an increased top line.”

A 355-strong fleet would help alleviate the overstretch and overwork that has worn down ships and sailors, and resulted in accidents and collisions to be expected from inadequately trained crews operating vessels deprived of needed maintenance. It would also give the Navy more muscle for simultaneously coping with an assertive China in the Pacific, a resurgent Russia in Europe, and regional threats such as Iran in the Persian Gulf. New ships would also give the Navy enough margin to retire older vessels.

But all this would be expensive. The Congressional Budget Office estimates that the building new ships would cost about $27 billion per year until 2047, and about the same amount for a mixture of new construction and refitting older ships that would result in a 355-ship force by 2028. “The smaller fleets would cost less,” CBO said. “If the Navy was kept at its current size, shipbuilding costs would average $22.4 billion annually. By contrast, if funding for the fleet was kept at roughly historical levels, shipbuilding costs would average $16.8 billion per year.”

Complicating the matter is that President Trump and Congress enacted a law in 2017 that officially specifies a fleet size of at least 355 ships. Nonetheless, even Secretary of the Navy Richard Spencer has called 355 “an aspirational goal.”

There is nothing magical about the 355 number. At the end of World War II, the U.S. Navy had 6,768 vessels. In 1987, during the Cold War defense buildup of President Reagan, the Navy had 594 ships, or more than double the current fleet size. Had someone proposed in 1987 that the Navy should have 6,768 ships, he would have dismissed as a fantasist.

How big a navy needs to be depends on numerous factors, such as the size and nature of the threats the fleet faces, whether the fleet is tasked with global commitments (which America will have for the foreseeable future), and whether fleets must operate for extended periods on overseas stations (another long-term problem for the U.S. Navy).

Put another way, if there isn’t enough money for a bigger navy, then either a degree of overstretch must be accepted, there needs to be some technological or tactical breakthrough to make each ship more efficient, or that navy’s commitments must be scaled back.

Does the U.S. Navy need 355 ships? The better question is, does the U.S. need to defend to Taiwan? Or Saudi Arabia? Or Western Europe? If the answer is yes, then the Navy needs more ships than it has now.

Michael Peck is a contributing writer for the National Interest. He can be found on Twitter and Facebook.

Image: Flickr.