Five Lexingtons would create an American fast wing

The American battle line is already full, but five completed Lexington-class battlecruisers would supply the fast wing central to US scouting doctrine. Congress might dislike the expense yet still accept the ships as part of the treaty bargain, while using their existence to reject later requests for 8-inch-gun cruisers. Converting only the sixth Lexington leaves the Navy with one fast carrier and may force a slower battleship hull into a second carrier conversion. Japan could face a similar battlecruiser-and-battleship conversion pattern after earthquake damage, making carrier speed a new operational constraint for both navies.