American 16- and 18-inch guns before Washington

What changes if Pennsylvania receives 16-inch guns and Colorado later moves to 18-inch guns?

Britain accelerates its own gun and speed response, later capital ships grow larger, and Washington-era gun and tonnage ceilings rise enough to preserve British 16.5-inch work and encourage an 18-inch British successor.

A 16-inch Pennsylvania laid down alongside Queen Elizabeth would signal the American caliber jump early enough to affect Britain's R class and its successors. An 18-inch Colorado would then set a higher negotiating baseline, likely pushing treaty displacement beyond 40,000 tons and making the British 16.5-inch G3 gun harder to prohibit. Hood or a following British design could emerge with true 18-inch armament rather than the historical 15-inch battery.