At the start of World War II , the Royal Navy was the strongest navy in the world, [ 1 ] with the largest number of warships built and with naval bases across the globe. Over the course of the war the United States Navy grew tremendously as the United States was faced with a two-front war on the seas. Navy was by far the largest and most powerful navy in the world with 6, ships, including 28 aircraft carriers, 23 battleships, 71 escort carriers, 72 cruisers, over submarines, destroyers, and thousands of amphibious, supply and auxiliary ships.
It also played a major supporting role, alongside the Royal Navy, in the European war against Germany. The December surprise attack on Pearl Harbor did knock out the battle fleet, but it did not touch the aircraft carriers, which became the mainstay of the rebuilt fleet.
Naval doctrine had to be changed overnight. King , the head of the Navy, to place primary emphasis on the small number of aircraft carriers. The U. Navy grew tremendously as it faced a two-front war on the seas. It achieved notable acclaim in the Pacific War , where it was instrumental to the Allies' successful " island hopping " campaign. Navy was operating 6, ships on V-J Day in August , including 28 aircraft carriers , 23 battleships , 71 escort carriers , 72 cruisers , over submarines , destroyers , and thousands of amphibious, supply and auxiliary ships.
The American war plan was Rainbow 5 and was completed on 14 May It assumed that the United States was allied with Britain and France and provided for offensive operations by American forces in Europe, Africa, or both.
The assumptions and plans for Rainbow 5 were discussed extensively in the Plan Dog memo , which concluded ultimately that the United States would adhere to a Europe first strategy, making the war against Germany a higher priority than the war against Japan. However President Roosevelt did not approve the plan—he wanted to play it by ear. It had stocks that would last a year or two.
