United States Navy in World War II

The United States Navy grew rapidly during World War II from 1941–45, and played the central role in the war against Japan, and a major role in the European war against Germany and Italy.

The U.S. Navy grew into a formidable force in the years prior to World War II, with battleship production being restarted in 1937, commencing with the USS North Carolina (BB-55). It was able to add to its fleets during the early years of the war while the US was still neutral, increasing production of vessels both large and small.

Though ultimately unsuccessful, Japan attempted to allay this strategic threat with the 1941 surprise attack on Pearl Harbor. Following American entry into the war, the U.S. Navy grew tremendously as the United States was faced with a two-front war on the seas. It achieved notable acclaim in the Pacific Theater, where it was instrumental to the Allies' successful "island hopping" campaign. The U.S. Navy fought six great battles with the Imperial Japanese Navy (IJN): the Attack on Pearl Harbor, Battle of the Coral Sea, the Battle of Midway, the Battle of the Philippine Sea, the Battle of Leyte Gulf, and the Battle of Okinawa.

By 1943, the Navy's size was larger than the combined fleets of all the other combatant nations in World War II. By war's end in 1945, the United States Navy had added hundreds of new ships, including 18 aircraft carriers and 8 battleships, and had over 70% of the world's total numbers and total tonnage of naval vessels of 1,000 tons or greater. At its peak, the U.S. Navy was operating 6,768 ships on V-J Day in August 1945, including 28 aircraft carriers, 23 battleships, 71 escort carriers, 72 cruisers, over 232 submarines, 377 destroyers, and thousands of amphibious, supply and auxiliary ships.

Doctrine had significantly shifted by the end of the war. The United States Navy had followed in the footsteps of the navies of Britain and Germany which favored concentrated groups of battleships as their main offensive naval weapons. The development of the aircraft carrier and its devastating utilization by the Japanese against the U.S. at Pearl Harbor however shifted U.S. thinking. The Pearl Harbor attack destroyed or took out of action most of the American battleships. This placed much of the burden of retaliating against the Japanese on the small number of aircraft carriers.

Iceland
On 16 June 1941, after negotiation with Churchill, Roosevelt ordered the United States occupation of Iceland to replace the British invasion forces. On 22 June 1941, the US Navy sent Task Force 19 (TF 19) from Charleston, South Carolina to assemble at Argentia, Newfoundland. TF 19 included 25 warships and the 1st Provisional Marine Brigade of 194 officers and 3714 men from San Diego, California under the command of Brigadier General John Marston. Task Force 19 (TF 19) sailed from Argentia on 1 July. On 7 July, Britain persuaded the Althing to approve an American occupation force under a U.S.-Icelandic defense agreement, and TF 19 anchored off Reykjavík that evening. U.S. Marines commenced landing on 8 July, and disembarkation was completed on 12 July. On 6 August, the U.S. Navy established an air base at Reykjavík with the arrival of Patrol Squadron VP-73 PBY Catalinas and VP-74 PBM Mariners. U.S. Army personnel began arriving in Iceland in August, and the Marines had been transferred to the Pacific by March, 1942. Up to 40,000 U.S. military personnel were stationed on the island, outnumbering adult Icelandic men (at the time, Iceland had a population of about 120,000.) The agreement was for the US military to remain until the end of the war (although the US military presence in Iceland remained through 2006).

Pearl Harbor
Pearl Harbor was one of the worst defeats in American history. The U.S. was caught by total surprise and the battle was completely one-sided. Admiral Isoroku Yamamoto, in overall command, argued the only way to win the war was to knock out the main American fleet immediately. His elaborately trained fleet approached within 200 mi of Hawaii without being detected. Admiral Chuichi Nagumo had tactical command. Over a five hour period his six carriers sent two waves of 350 dive-bombers, torpedo planes and fighters. They destroyed or severely damaged eight battleships, ten smaller warships, and 230 aircraft; 2,400 American soldiers and sailors were killed. Japanese losses were negligible--29 planes shot down (several American planes were also shot down by anti-aircraft fire by mistake). Commander Minoru Genda, the chief planner of the raid, begged Nagumo to strike again at the shore facilities, oil storage tanks, and submarines, and to hunt down the American carriers that were supposedly nearby. But Nagumo, having just smashed the Americans in one of the greatest victories of naval history, decided not to risk further action. Japanese success was due to courage, good equipment, excellent pilots, total surprise, and above all, a daring and imaginative plan. To even reach Pearl Harbor they had to learn how to refuel at sea (a technique the US Navy already had worked out); to sink all those ships they used their superb electric torpedoes and perfected shallow-water bombing tactics. Surprise was decisive. While everyone knew that war was imminent, no one at Pearl expected an attack. The commanders had been complacent about routine defensive measures. Even if the defense had been more alert, the surprise and overwhelming power of the Japanese strike probably would have been decisive.

But in the broader perspective, the attack was a failure. The lost battleships reflected obsolete doctrine and were not needed; the lost planes were soon replaced; the casualty list was short by World War II standards; perhaps most importantly, the US did not lose its three aircraft carriers. Tokyo's calculation that the Americans would lose heart and seek a compromise peace within a few months proved wildly wrong--the "sneak attack" electrified public opinion, committing America with near unanimity to a war to the death against the Japanese Empire.

Aftermath
After Pearl Harbor the Imperial Japanese Navy (IJN) seemed unstoppable because it outnumbered and outgunned the disorganized Allies--US, Britain, Netherlands, Australia, China. London and Washington both believed in Mahanian doctrine, which stressed the need for a unified fleet. However, in contrast to the cooperation achieved by the armies, the Allied navies failed to combine or even coordinate their activities until mid-1942. Tokyo also believed in Mahan, who said command of the seas --achieved by great fleet battles--was the key to sea power. Therefore the IJN kept its main strike force together under Admiral Yamamoto and won a series of stunning victories over the Americans and British in the 90 days after Pearl Harbor.

Outgunned at sea, with its big guns lying at the bottom of Pearl Harbor, the American strategy for victory required a slow retreat or holding action against the IJN until the much greater industrial potential of the US could be mobilized to launch a fleet capable of projecting Allied power to the enemy heartland.

Guadalcanal
Guadalcanal, fought from August 1942 to February 1943, was the first major Allied offensive of the war in the Pacific Theater. This campaign saw American air, naval and ground forces (later augmented by Australians and New Zealanders) in a six months campaign slowly overwhelm determined Japanese resistance. Guadalcanal was the key to control the Solomon Islands, which both sides saw as strategically essential. Both sides won some battles but both sides were overextended in terms of supply lines.

The rival navies fought seven battles, with the two sides dividing the victories. They were: Battle of Savo Island, Battle of the Eastern Solomons, Battle of Cape Esperance, Battle of the Santa Cruz Islands, Naval Battle of Guadalcanal, Battle of Tassafaronga and Battle of Rennell Island. Both sides pulled out its aircraft carriers, as they were too vulnerable to land-based aviation.

Midway
The Battle of Midway, together with the Guadlcanal campaign, marked the turning point in the Pacific. Between June 4-7, 1942, the United States Navy decisively defeated a Japanese naval force that had sought to lure the U.S. carrier fleet into a trap at Midway Atoll. The Japanese fleet lost four aircraft carriers to the U.S. Navy's one American carrier and a destroyer. After Midway, and the exhausting attrition of the Solomon Islands campaign, Japan's shipbuilding and pilot training programs were unable to keep pace in replacing their losses while the U.S. steadily increased its output in both areas. Military historian John Keegan called the Battle of Midway "the most stunning and decisive blow in the history of naval warfare."

1943
In preparation of the recapture of the Philippines, the Allies started the Gilbert and Marshall Islands campaign to retake the Gilbert and Marshall Islands from the Japanese in summer 1943. Enormous effort went into recruiting and training sailors and Marines, and building warships, warplanes and support ships in preparation for a thrust across the Pacific, and to support Army operations in the Southwest Pacific, as well as in Europe and North Africa.

1944
The Navy continued its long movement west across the Pacific, seizing one island base after another. Not every Japanese stronghold had to be captured; some, like the big bases at Truk, Rabaul and Formosa were neutralized by air attack and then simply leapfrogged. The ultimate goal was to get close to Japan itself, then launch massive strategic air attacks and finally an invasion. The US Navy did not seek out the Japanese fleet for a decisive battle, as Mahanian doctrine would suggest; the enemy had to attack to stop the inexorable advance.

Battle of the Philippine Sea
The climax of the carrier war came at the Battle of the Philippine Sea.

Taking control of islands that could support airfields within B-29 range of Tokyo was the objective. 535 ships began landing 128,000 Army and Marine invaders on June 15, 1944 in the Mariana and Palau Islands. The achievement in planning such a complex logistical operation in just ninety days, and staging it 3,500 mi from Pearl Harbor was indicative of American logistic superiority. (The previous week an even bigger landing force hit the beaches of Normandy--by 1944 the Allies had resources to spare.)

The Japanese launched an ill-coordinated attack on the larger American fleet; its planes operated at extreme ranges and could not keep together, allowing them to be easily shot down in what Americans jokingly called the "Great Marianas Turkey Shoot."

Japan had now lost all its offensive capabilities, and the U.S. had control of Guam, Saipan and Tinian islands that provided air bases within range of B-29 bombers targeted at Japan's home islands. It was entirely an air battle, in which Americans had all the technological advantages. It was the largest naval battle in history, to day, surpassed only by the Battle of Leyte Gulf in October 1944.

Japanese strategy
The American 5th Fleet covering the landing comprised 15 big carriers and 956 planes, plus 28 battleships and cruisers, and 69 destroyers. Tokyo sent Vice Admiral Jisaburo Ozawa with nine-tenths of Japan's fighting fleet--it was about half the size of the American force, and included nine carriers with 473 planes, 18 battleships and cruisers, and 28 destroyers. Ozawa's pilots boasted of their fiery determination, but they had only a fourth as much training and experience as the Americans. They were outnumbered 2-1 and used inferior equipment. Ozawa had anti-aircraft guns but lacked proximity fuzes and good radar.

Ozawa gambled on surprise, luck and a trick strategy, but his battle plan was so complex and so dependent on good communications that it quickly broke down. His planes carried more gasoline because they were not weighted down with protective armor; they could attack at 300 mi, and could search a radius of 560 miles. The heavier American Hellcats could only attack to 200 mi, and only search to 325. Ozawa's plan therefore was to use his advantage in range by positioning his fleet 300 mi out, forcing the Americans to search over 150,000 sqmi of ocean just to find him. The Japanese ships would stay beyond American range, but their planes would have enough range to strike the American fleet. They would hit the carriers, land at Guam to refuel, then hit the Americans en route back to their carriers. Ozawa counted heavily on the 500 or so ground- based planes that had been flown ahead to Guam and other islands in the area.

Okinawa
Okinawa was the last great battle of the entire war. The goal was to make the island into a staging area for the invasion of Japan scheduled for fall 1945. It was just 350 miles (550 km) south of the Japanese home islands. Marines and soldiers landed on 1 April 1945, to begin an 82-day campaign which became the largest land-sea-air battle in history and was noted for the ferocity of the fighting and the high civilian casualties with over 150,000 Okinawans losing their lives. Japanese kamikaze pilots enacted the largest loss of ships in U.S. naval history with the sinking of 38 and the damaging of another 368. Total U.S. casualties were over 12,500 dead and 38,000 wounded, while the Japanese lost over 110,000 men. The fierce combat and high American losses led the Navy to oppose an invasion of the main islands. An alternative strategy was chosen: using the atomic bomb to induce surrender.

Naval technology
Technology and industrial power proved decisive. Japan failed to exploit its early successes before the immense potential power of the Allies could be brought to bear. In 1941 the Japanese Zero fighter had a longer range and better performance than rival American warplanes, and the pilots had more experience in the air. But Japan never improved the Zero and by 1944 the Allied navies were far ahead of Japan in both quantity and quality, and ahead of Germany in quantity and in putting advanced technology to practical use. High tech innovations arrived with dizzying rapidity. Entirely new weapons systems were invented--like the landing ships, such as the 3,000 ton LST ("Landing Ship Tank") that carried 25 tanks thousands of miles and landed them right on the assault beaches. Furthermore, older weapons systems were constantly upgraded and improved. Obsolescent airplanes, for example, received more powerful engines and more sensitive radar sets. One impediment to progress was that admirals who had grown up with great battleships and fast cruisers had a hard time adjusting their war-fighting doctrines to incorporate the capability and flexibility of the rapidly evolving new weapons systems.

Ships
The ships of the American and Japanese forces were closely matched at the beginning of the war. By 1943 the American qualitative edge was winning battles; by 1944 the American quantitative advantage made the Japanese position hopeless. The German Navy, distrusting its Japanese ally, ignored Hitler's orders to cooperate and failed to share its expertise in radar and radio. Thus the Imperial Navy was further handicapped in the technological race with the Allies (who did cooperate with each other). The United States economic base was ten times larger than Japan's, and its technological capabilities also significantly greater, and it mobilized engineering skills much more effectively than Japan, so that technological advances came faster and were applied more effectively to weapons. Above all, American admirals adjusted their doctrines of naval warfare to exploit the advantages. The quality and performance of the warships of Japan were initially comparable to that of the US.

The Americans were supremely, and perhaps overly, confident in 1941. Pacific commander Admiral Chester W. Nimitz boasted he could beat a bigger fleet because of "...our superior personnel in resourcefulness and initiative, and the undoubted superiority of much of our equipment." As Willmott notes, it was a dangerous and ill-founded assumption.

Battleships
The American battleships before Pearl Harbor could fire salvos of nine 2,100 pound armor-piercing shells every minute to a range of 35,000 yards (19 miles). No ship except another battleship had the thick armor that could withstand that kind of firepower. When intelligence reported that Japan had secretly built even more powerful battleships, Washington responded with four "Iowa" class battleships (two of which were used a half-century later in the Gulf War.) The "big-gun" admirals on both sides dreamed of a great shootout at twenty-mile (32 km) range, in which carrier planes would be used only for spotting the mighty guns. Their doctrine was utterly out of date. A plane like the Grumman TBF Avenger could drop a 2,000 pound bomb on a battleship at a range of hundreds of miles. An aircraft carrier cost less, required about the same number of personnel, was just as fast, and could easily sink a battleship. During the war the battleships found new missions: they were platforms holding all together dozens of anti-aircraft guns and 8 or 9 14" or 16" long-range guns used to blast land targets before amphibious landings. Their smaller 5" guns, and the 4,800 3" to 8" guns on cruisers and destroyers also proved effective at bombarding landing zones. After a short bombardment of Tarawa island in November 1943, Marines discovered that the Japanese defenders were surviving in underground shelters. It then became routine doctrine to thoroughly work over beaches with thousands of high explosive and armor piercing shells. The bombardment would destroy some fixed emplacements and kill some troops.  More important, it severed communication lines, stunned and demoralized the defenders, and gave the landing parties fresh confidence.  After the landing, naval gunfire directed by ground observers would target any enemy pillboxes that were still operational.  The sinking of the battleships at Pearl Harbor proved a blessing in deep disguise, for after they were resurrected and assigned their new mission they performed well. (Absent Pearl Harbor, big-gun admirals like Raymond Spruance might have followed prewar doctrine and sought a surface battle in which the Japanese would have been very hard to defeat.)

Naval aviation
In World War I the Navy explored aviation, both land-based and carrier based. However the Navy nearly abolished aviation in 1919 when Admiral William S. Benson, the reactionary Chief of Naval Operations, could not "conceive of any use the fleet will ever have for aviation", and he secretly tried to abolish the Navy's Aviation Division. Assistant Secretary of the Navy Franklin D. Roosevelt reversed the decision because he believed aviation might someday be "the principal factor" at sea with missions to bomb enemy warships, scout enemy fleets, map mine fields, and escort convoys. Grudgingly allowing it a minor mission, the Navy slowly built up its aviation. In 1929 it had one carrier (USS Langley (CV-1)), 500 pilots and 900 planes; by 1937 it had 5 carriers (the USS Lexington (CV-2), USS Saratoga (CV-3), Ranger, USS Yorktown (CV-5) and USS Enterprise (CV-6)), 2000 pilots and 1000 much better planes. With Roosevelt now in the White House, the tempo soon quickened. One of the main relief agencies, the PWA, made building warships a priority. In 1941 the U.S. Navy with 8 carriers, 4,500 pilots and 3,400 planes had more airpower than the Japanese Navy.

Battles

 * Bennett, Geoffrey. Naval Battles of World War Two (Pen & Sword Military Classics) (2003)
 * Blair, Clay Silent Victory: The U.S. Submarine War Against Japan. (Annapolis: Naval Institute Press, 2001). ISBN 1-55750-217-X.
 * Lundstrom, John B. The First Team: Pacific Naval Air Combat from Pearl Harbor to Midway (Naval Institute Press, 1984) ISBN 0-87021-189-7
 * Morison, Samuel Eliot. The Two-Ocean War: A Short History of the United States Navy in the Second World War (1963)ISBN 1591145244
 * Morison, History of United States Naval Operations in World War II. Vol. 3, The Rising Sun in the Pacific. Boston: Little, Brown, 1961; Vol. 4, Coral Sea, Midway and Submarine Actions. 1949; Vol. 5, The Struggle for Guadalcanal. 1949; Vol. 6, Breaking the Bismarcks Barrier. 1950; Vol. 7, Aleutians, Gilberts, and Marshalls. 1951; Vol. 8, New Guinea and the Marianas. 1962; Vol. 12, Leyte. 1958; vol. 13, The Liberation of the Philippines: Luzon, Mindanao, the Visayas. 1959; Vol. 14, Victory in the Pacific. 1961.
 * Prange, Gordon. At Dawn We Slept (Penguin Books, 1982). ISBN 0-10-064550-9 on Pearl Harbor
 * Smith, Peter C. Midway, Dauntless Victory: Fresh Perspectives on America's Seminal Naval Victory of World War II (2007)
 * Smith, Steven. Wolf Pack: The American Submarine Strategy That Helped Defeat Japan (2003)
 * Tillman, Barrett. Clash of the Carriers: The True Story of the Marianas Turkey Shoot of World War II (2005).
 * Y'Blood William T. The Little Giants: U.S. Escort Carriers Against Japan (1999)

Ships and technology

 * Campbell, N. J. M. Naval Weapons of World War Two (2002), covers major navies of the world
 * Friedman, Norman. U.S. Naval Weapons: Every Gun, Missile, Mine and Torpedo Used by the U.S. Navy from 1883 to the Present Day (1983)
 * Jane's Fighting Ships of World War II (1972); covers major navies of the world

Admirals and strategies

 * Buell, Thomas. The Quiet Warrior: A Biography of Admiral Raymond Spruance. (1974).
 * Buell, Thomas B. Master of Sea Power: A Biography of Fleet Admiral Ernest J. King (Naval Institute Press, 1995). ISBN 1-55750-092-4
 * Miller, Edward S. War Plan Orange: The U.S. Strategy to Defeat Japan, 1897-1945 (1991)
 * Larrabee, Eric. Commander in Chief: Franklin Delano Roosevelt, His Lieutenants, and Their War (2004), chapters on all the key American war leaders excerpt and text search
 * Potter, E. B. Bull Halsey  (1985).
 * Potter, E. B. Nimitz.  (1976).

Sailors and personal viewpoints

 * Hands to action stations!: Naval poetry and verse from World War Two (Bluejacket Books, 1980)
 * Haberstroh, Jack, ed. SWABBY: World War II Enlisted Sailors Tell It Like It Was (2003) recollections* Hoyt, Edwin. Now Hear This: The Story of American Sailors in World War II (1993)
 * Sowinski, Larry. Action in the Pacific: As Seen by US Navy Photographers During World War 2 (1982)
 * Wukovits, John F. Black Sheep: The Life of Pappy Boyington (2011)