Carrier politics channel Japan toward the Haruna design

Japan's Defense Agency considered a helicopter carrier during its second build-up plan but encountered domestic political objections. The alternative was to place aviation on destroyers and give escort groups a hub ship around which smaller ASW vessels could operate. Haruna consequently reached roughly the displacement of a Second World War light cruiser while retaining the destroyer label and a flight deck long enough for simultaneous helicopter operations. The mission resembled Britain's Invincible decision: both navies wanted to maximize embarked ASW aviation, but one chose a through-deck cruiser and the other a large flight-deck destroyer. The result expanded both fleet aviation and Japanese experience building much larger warships.