Even by WWII the futility of trying to armor-plate aircraft carriers like battleships was already recognized. The British put some armor on their aircraft carri

Even by WWII the futility of trying to armor-plate aircraft carriers like battleships was already recognized. The British put some armor on their aircraft carrier flight decks to give some defense against land-based bombers, but in the Pacific, neither the US nor Japan did this, leading to outcomes like Midway.