How would the powers have reinforced their Pacific bases if Article 19 had never existed?
Short answerThey likely would have entered a fortification race, because stronger bases required fewer fleet units to defend them.
NotesThe counterfactual shows what the treaty restriction was intended to prevent. Japan could have strengthened its island bases, prompting Britain and the United States to reinforce their own positions in response. Secure fortifications reduce the number of ships needed for local defence and improve a fleet's ability to operate forward. Removing Article 19 would therefore shift part of the naval arms race from hulls to bases, docks, guns, and supply infrastructure.