Carrier development without the Washington Naval Treaty

Would navies still have invested heavily in carriers without the Washington Naval Treaty?

Britain probably would, potentially through an Admiral-class conversion, while American and Japanese choices are less certain.

Circumstantial evidence suggests that Cammell Laird may have gained strike-carrier experience from an Admiral-class conversion study before Ark Royal. British interest would still have been driven by attacks on fleets in harbor and the need to protect trade from surface raiders. That probable British path differs from the less certain American and Japanese response, especially given Japan's continuing conservatism about battle fleets. The reasoning is provisional because the archival clues fall short of conclusive proof.