Was the naval gun race truly global?

Was the battleship gun-caliber race broader than Britain competing with Germany?

Yes. American and Italian caliber increases were major reasons Britain kept enlarging its guns, making the technological race multinational.

If Germany had been the Royal Navy's only benchmark, improved 12-inch and 13.5-inch guns could have remained sufficient for longer. The American and Italian move toward heavier weapons created a technological competition that crossed national pairings and made the prewar naval race global rather than merely Anglo-German.