A modern naval treaty needs the largest fleets

Could a Washington-style naval limitation treaty be reintroduced in the modern era?

Only with great difficulty, and an agreement would have little value unless it included both the United States and China.

The first problem is deciding which states would sign and accept limits. A naval agreement cannot restrain competition if either of the two largest relevant fleets remains outside it. U.S. and Chinese participation would therefore be essential. Questions about ratios, ship categories, or tonnage ceilings only become useful after the principal competitors accept the same framework.