Britain and the United States would continue beyond their late-1930s carrier designs rather than freeze the Illustrious or Essex patterns. On roughly 27,000 tons, each could produce a capable armoured fleet carrier with a substantial air group. The British design would probably accept fewer aircraft for more protection because the Royal Navy expects to operate under land-based air attack in the Mediterranean and South China Sea as well as in the oceans. The American design could trade some armour for aircraft because those enclosed-water threats are less central to its expected routes. Doctrine and geography would shape the ships even when both industrial powers had access to similar technology.
Notable Point · 58:59-1:00:11
Why British and American carriers would still diverge
A delayed war may move both navies toward larger armoured carriers, but their operating geography still produces different balances of armour and aircraft capacity.