Based on factual materials and documents, US Navy Admiral C. Nimitz and E. Potter talk about the most important naval operations of World War II in the Atlantic, the Mediterranean Sea and the Pacific Ocean. World War II is almost impossible to compare with any previous military clash. It was conducted by more numerous and diverse weapons. She has no equal in history in the number of people participating in it and in the variety of military operations. Since World War II was a world war in the full sense of the word, it was fought mainly by naval forces. Allied navies moved armies across the seas and oceans to enemy shores, played the main (and sometimes the only) role in isolating future bridgeheads in order to deprive the enemy of the opportunity to deliver reinforcements, smashed the enemy fleet and inflicted heavy losses on it, landed invasion forces, supported them with naval artillery fire and aircraft carrier aircraft, supplied them with everything they needed and delivered reinforcements to them, despite counterattacks by air, surface and submarine forces of the enemy. In meeting these challenges, the United States Navy grew into a huge and complex organization that operated on land, at sea, and in the air, building and maintaining military power in overseas territories.