American battle-line politics enable the compromise

The Dominion plan works politically only if American leaders do not treat every battlecruiser as equivalent to a battleship. The Senate remained focused on the strength and equality of the battle line. Battlecruisers were understood as fast scouts and cruiser killers rather than the ships that decided a fleet engagement. Completing the Lexingtons gives the United States its own answer without reopening the battleship ratio. That doctrinal and political distinction makes an apparent British imperial advantage acceptable within the treaty bargain.