In November 1921 the first purpose-built aircraft carrier was launched by the Japanese, followed a year later by the launch of the British Hermes.
The conversion of battlecruisers into aircraft carriers after World War I required the consideration of issues including handling aircraft on the flight deck and the techniques of attacking enemy ships, and the evolution of carrier operations was ongoing when World War II broke out.
With a focus on the conflict in the Pacific between the U.
Navy .