31.5.3: The Guadalcanal Campaign

The Guadalcanal Campaign, also known as the Battle of Guadalcanal and code-named Operation Watchtower, originally referred to an operation to take the island of Tulagi by Allied forces. This military campaign was fought between August 7, 1942, and February 9, 1943, on and around the island of Guadalcanal in the Pacific theater of World War II. It was the first major offensive by Allied forces against the Empire of Japan.

Overview

On August 7, 1942, Allied forces, predominantly United States Marines, landed on the islands of Guadalcanal, Tulagi, and Florida in the southern Solomon Islands with the objective of denying their use by the Japanese to threaten Allied supply and communication routes between the U.S., Australia, and New Zealand. The Allies also intended to use Guadalcanal and Tulagi as bases to support a campaign to capture or neutralize the major Japanese base at Rabaul on New Britain. The Allies overwhelmed the outnumbered Japanese defenders, who had occupied the islands since May 1942, and captured Tulagi and Florida, as well as an airfield (later named Henderson Field) that was under construction on Guadalcanal. Powerful American and Australian naval forces supported the landings.

Surprised by the Allied offensive, the Japanese made several attempts between August and November to retake Henderson Field. Three major land battles, seven large naval battles (five nighttime surface actions and two carrier battles), and continual, almost daily aerial battles culminated in the decisive Naval Battle of Guadalcanal in early November, in which the last Japanese attempt to bombard Henderson Field from the sea and land with enough troops to retake it was defeated. In December, the Japanese abandoned their efforts to retake Guadalcanal and evacuated their remaining forces by February 7, 1943, in the face of an offensive by the U.S. Army’s XIV Corps.

The Guadalcanal campaign was a significant strategic combined arms Allied victory in the Pacific theater. Along with the Battle of Midway, it has been called a turning-point in the war against Japan. The Japanese reached the peak of their conquests in the Pacific. The victories at Milne Bay, Buna-Gona, and Guadalcanal marked the Allied transition from defensive operations to strategic initiative, leading to offensive operations such as the Solomon Islands, New Guinea, and Central Pacific campaigns that eventually resulted in Japan’s surrender and the end of World War II.

Background

On December 7, 1941, Japanese forces attacked the United States Pacific Fleet at Pearl Harbor, Hawaii. The attack crippled much of the U.S. battleship fleet and precipitated an open and formal war between the two nations. The initial goals of Japanese leaders were to neutralize the U.S. Navy, seize possessions rich in natural resources, and establish strategic military bases to defend Japan’s empire in the Pacific Ocean and Asia. To further those goals, Japanese forces captured the Philippines, Thailand, Malaya, Singapore, Burma, the Dutch East Indies, Wake Island, Gilbert Islands, New Britain, and Guam. Joining the U.S. in the war against Japan were the rest of the Allied powers, several of whom, including the United Kingdom, Australia and the Netherlands, had also been attacked by Japan.

Two attempts by the Japanese to continue their strategic initiative and offensively extend their outer defensive perimeter in the south and central Pacific to where they could threaten Australia and Hawaii or the U.S. West Coast were thwarted at the naval battles of Coral Sea and Midway respectively. Coral Sea was a tactical stalemate, but a strategic Allied victory which became clear only much later. Midway was not only the Allies’ first major victory against the Japanese, it significantly reduced the offensive capability of Japan’s carrier forces but did not change their offensive mindset for several crucial months in which they compounded mistakes by moving ahead with brash decisions such as the attempt to assault Port Moresby over the Kokoda trail. Up to this point, the Allies were on the defensive in the Pacific, but these strategic victories provided them an opportunity to seize the initiative from Japan.

Significance

The Battle of Guadalcanal was one of the first prolonged campaigns in the Pacific, alongside the related and concurrent Solomon Islands campaign. Both were battles that strained the logistical capabilities of the combatant nations. For the United States, this need prompted the development of effective combat air transport for the first time. A failure to achieve air superiority forced Japan to rely on reinforcement by barges, destroyers, and submarines, with very uneven results. Early in the campaign, the Americans were hindered by a lack of resources as they suffered heavy losses in cruisers and carriers, with replacements from ramped-up shipbuilding programs still months away.

The U.S. Navy suffered such high personnel losses during the campaign that it refused to publicly release total casualty figures for years. However, as the campaign continued and the American public became more and more aware of the plight and perceived heroism of the American forces on Guadalcanal, more forces were dispatched to the area. This spelled trouble for Japan as its military-industrial complex was unable to match the output of American industry and manpower. As the campaign wore on, the Japanese were losing irreplaceable units while the Americans were rapidly replacing and even augmenting their forces.

The Guadalcanal campaign was costly to Japan both strategically and in material losses and manpower. Roughly 30,000 personnel, including 25,000 experienced ground troops, died during the campaign. As many as three-quarters of the deaths were from non-combat causes such as starvation and tropical diseases. The drain on resources directly contributed to Japan’s failure to achieve its objectives in the New Guinea campaign.

After the victory at the Battle of Midway, America was able to establish naval parity in the Pacific. However, this alone did not change the direction of the war. It was only after the Allied victories in Guadalcanal and New Guinea that the Japanese offensive thrust was ended and the strategic initiative passed to the Allies permanently. The Guadalcanal Campaign ended all Japanese expansion attempts and placed the Allies in a position of clear supremacy. It can be argued that this Allied victory was the first step in a long string of successes that eventually led to the surrender of Japan and the occupation of the Japanese home islands.

The “Europe first” policy of the United States initially only allowed for defensive actions against Japanese expansion to focus resources on defeating Germany. However, Admiral King’s argument for the Guadalcanal invasion and its successful implementation convinced President Franklin D. Roosevelt that the Pacific Theater could be pursued offensively as well. By the end of 1942, it was clear that Japan had lost the Guadalcanal campaign, a serious blow to Japan’s strategic plans for defense of its empire and an unanticipated defeat at the hands of the Americans.

Perhaps as important as the military victory for the Allies was the psychological victory. On a level playing field, the Allies had beaten Japan’s best land, air, and naval forces. After Guadalcanal, Allied personnel regarded the Japanese military with much less fear and awe than they had previously. In addition, the Allies viewed the eventual outcome of the Pacific War with increased optimism.