The Pacific War between the United States and Japan began on December 7, 1941 when Japan’s powerful carrier fleet launched a bold attack to catch the US Navy in its primary base at Pearl Harbor. This attack was successful in changing the predicted course of the naval war in the Pacific, which was shared by both sides. No longer would the war be decided by a clash of battlefleets somewhere in the western Pacific. Air power was now the dominant factor in the Pacific, and naval air power would be the cutting edge of both the US and Imperial navies.
Seizing upon the advantage offered by the crippling of the US Pacific Fleet in Pearl Harbor, the Japanese quickly moved to attain their objectives. After sinking two British capital ships sent to the Pacific to operate from Singapore, the Imperial Navy succeeded in brushing aside weak Allied naval opposition around the Dutch East Indies. The Battle of the Java Sea on February 27 marked the end of any coherent Allied naval defense of the East Indies. It also provided an insight into the strength of the Imperial Navy’s cruiser force. To cover their invasion of Java, the Japanese employed a screening force of two heavy cruisers (Nachi and Haguro), two light cruisers, and 14 destroyers. The Allies assembled a mixed force of American, British, Australian, and Dutch ships, which on paper looked to be an even match for the Japanese. This force included two heavy cruisers (the American Houston and another Treaty heavy cruiser, the British Exeter), another three light cruisers, and nine destroyers. The battle began with an exchange of 8-inch gunfire at long range. This was inconclusive, and was followed by a barrage of 39 Type 93 torpedoes from Haguro, the two light cruisers, and six destroyers. The results were disappointing for the Japanese, with only a single Dutch destroyer hit and sunk; however this hit and an 8-inch shell hit on Exeter, which reduced her speed, threw the Allied force into confusion.
A view of the Northampton-class cruiser Houston taken in April 1935. The ship in the background is a New Orleans-class cruiser and the differences between the Northampton and New Orleans classes are evident. Houston became the first US Navy Treaty cruiser lost during the war when she was sunk by a Japanese force including the cruisers Mogami and Mikuma on March 1, 1942 in the Sunda Strait. (US Naval Historical Center)
In the second phase of the battle, another mass Japanese torpedo attack of 98 torpedoes, including 16 from the heavy cruisers, rendered no results. In addition, 302 Japanese 8-inch shells also failed to score. The third phase of battle was conducted at night. Four remaining Allied cruisers without destroyer escort again attempted to attack the Japanese invasion convoy. Lookouts aboard Nachi spotted the Allied force at 16,000 yards and within minutes another exchange of gunfire ensued, followed by another 12 torpedoes from Nachi and Haguro. Each of the two Dutch light cruisers was struck by a single torpedo and sank quickly, effectively bringing the battle to an end. In total, two Allied cruisers and three destroyers were sunk against no losses for the Japanese. Though the battle resulted in a Japanese victory, their performance was not overly impressive. The Japanese had launched 153 torpedoes for only three hits, but these were the decisive hits of the battle. Heavy-cruiser gunfire was even less impressive, with only five hits from the 1,619 8-inch shells expended.
While completing the planned conquest of the East Indies, the Japanese were also successfully seizing First Operational Phase objectives in the South Pacific. The large harbor at Rabaul, located on New Britain, was captured on January 23, 1942. To defend Rabaul, the Japanese considered also capturing other points on New Britain, Tulagi in the Solomons, and key areas on Eastern New Guinea to establish an interconnecting web of airfields with which to fend off potential Allied attacks. On January 29, the Naval General Staff approved the first phase of these operations. Lae and Salamaua, located on southeastern New Guinea, were taken on March 8.
Admiral Ernest King, the moving force behind overall US Navy strategy, was very concerned about the growing Japanese menace in the south Pacific and the possibility that the Japanese would succeed in cutting the sea lines of communications between the US and Australia. King was determined not only to secure these critical maritime links, but also to launch an offensive in the region at the earliest opportunity. Following the Japanese seizure of Lae and Salamaua, the US Navy intervened with a two-carrier strike on the Japanese invasion force. Damage to the Japanese was slight, but it gave them reason to pause before pushing on to Port Moresby and Tulagi. In early April, it was decided to detach two of the fleet carriers from the Imperial Navy’s carrier striking force to support future operations in the south Pacific. The next phase of Japanese operations began successfully with the seizure of Tulagi on May 3. The counterattack by an American carrier force led to a clash with the Japanese carriers covering the operation. This action, the Battle of Coral Sea, resulted in heavy carrier losses for both sides but stopped further Japanese expansion in the south Pacific.
Chokai pictured in Truk during the war with a Yamato-class battleship in the background. Because of her duties as a flagship, she never returned to Japan to undergo extensive modernization and she remained the least modified Takao-class unit. When she was sunk in October 1944 by air attack during the Battle of Leyte Gulf, she still retained her single 4.7-inch guns and triple torpedo mounts. (Yamato Museum)
Myoko as completed in 1929. In her early configuration, she possessed a main battery of 7.9-inch guns and a secondary battery of six 4.7-inch guns. The fixed torpedo battery of six tubes on each beam can be made out just under the single catapult. (Yamato Museum)
Following the clash at Coral Sea, both sides turned their attention to the central Pacific. In a bid for a decisive battle to destroy the US Pacific Fleet, the Japanese launched an attempted invasion of Midway Atoll, but were themselves ambushed with the loss of four carriers. However, even following the disaster at Midway, the Imperial Navy retained an edge overall in the naval balance. In the Pacific, the US Navy deployed four fleet carriers, seven battleships, 14 heavy cruisers, 13 light cruisers, and 80 destroyers. The Imperial Navy still retained four heavy carriers, three light carriers, 12 battleships, 17 heavy cruisers, 20 light cruisers, and 106 destroyers.
Following the Midway interlude, both sides turned their attentions to the south Pacific. On June 13, the Japanese decided to place an airbase on Guadalcanal, the large island directly across from Tulagi where the Japanese had already established a seaplane base. On July 6, two construction units arrived in Guadalcanal to begin work on an airfield.
By the time this work had begun, the Americans were already taking steps to ensure that it would never be completed – or at least not under Japanese control. On June 24, King directed Admiral Nimitz to recapture Tulagi and neighboring areas. By 5 July, planning was already in progress and Guadalcanal was added as a target. Planning was conducted at a frenetic pace and forces were hurriedly marshaled to execute it. The landing would be conducted by the hastily assembled and untested 1st Marine Division and supported by 82 ships under Vice-Admiral Frank Fletcher. These were divided into the Air Support Force with three of the Pacific Fleet’s remaining carriers, and an Amphibious Force to land and support the Marines.
Despite the accelerated and, at times, haphazard preparations, the landings on August 7, 1942 went well. Tulagi was captured after a short, fierce fight. On Guadalcanal, Japanese resistance was light, and by the afternoon of August 8 the airfield had been seized.
The Japanese response to the first American offensive of the war was immediate. On August 7 and 8, aircraft from Rabaul attacked the invasion fleet. Both raids resulted in heavy Japanese losses and failed to disrupt the American landing. However a stronger Japanese reaction was already in motion. By the evening of August 7, Admiral Mikawa had already sortied with all available forces, including five heavy cruisers, to strike the American beachhead.