If the US Navy jumped from twelve- to fifteen-inch guns

What if Congress ordered the US Navy to move directly from twelve-inch to fifteen-inch guns?

The new caliber would delay American ships and provoke a wider gun-caliber competition rather than a simple like-for-like British response.

Developing fifteen-inch guns directly after twelve-inch weapons would delay American construction and complicate ammunition logistics. The New York class would be the immediate ships affected in this hypothetical. British prestige and the cost of adding an intermediate calibre are offered as reasons for a larger response, probably sixteen-and-a-half-inch guns for the Queen Elizabeth class. A larger British ship and a modest design delay could also create room for additional machinery and greater speed. Germany and other naval powers would then face a more difficult attempt to catch up with the enlarged Anglo-American gun competition.