The Guadalcanal Campaign, 1942 to 1943: the Pacific turns

In August 1942 the United States took the offensive in the Pacific for the first time, landing Marines on a jungle island few had heard of: Guadalcanal. The six-month struggle that followed, on land, at sea and in the air, broke the momentum of Japan's war.²

Part of The greatest battles of the Pacific War · Before: The Battle of Midway · Next: The Battle of Tarawa · Key figures: John Basilone, Chesty Puller

Who won the Battle of Guadalcanal and why?

The Allies, above all the United States, won. Japan withdrew its last troops in February 1943 because it could not keep its army on the island supplied: aircraft from Henderson Field ruled the nearby waters by day, Japanese reinforcements came in piecemeal by night, and combat, hunger and disease destroyed two thirds of the 36,000 men Japan sent.³

The first Allied offensive

After stopping Japan at the Coral Sea and Midway, the Allies went over to the attack. On 7 August 1942 US Marines landed on Guadalcanal and on Tulagi and the islets nearby, and seized a half-built Japanese airfield. They named it Henderson Field, after Major Lofton Henderson, a Marine aviator killed at Midway. Holding that airfield became the key to the whole campaign.⁴

The plan came from Admiral Ernest King, commander in chief of the US Fleet, who wanted to keep the initiative won at Midway, as the historian Robert Citino writes for the National WWII Museum. By July Allied reconnaissance had found the Japanese building an airstrip on Guadalcanal, from which bombers could reach the sea lanes between the United States and Australia. The operation, code-named Watchtower, was put together in such a hurry that the men who carried it out called it Operation Shoestring.⁵

More than 19,000 Marines sailed with the landing force, by the count of the US Army's official history. Most went ashore on Guadalcanal itself, where the small Japanese garrison fled into the jungle and left its stores behind. The fighting was much harder on Tulagi and the islets of Gavutu and Tanambogo, where the Japanese garrisons fought back from caves and dugouts.⁶

On the night of 8 to 9 August a Japanese cruiser force under Vice Admiral Gunichi Mikawa surprised the Allied screen off Savo Island and sank four heavy cruisers, three American and the Australian Canberra. The naval historian Samuel Eliot Morison called the Battle of Savo Island one of the worst defeats ever inflicted on the United States Navy; Citino calls it the worst in its history.⁷

The commanders' decisions

Two decisions taken on the first evening shaped the campaign. Worried by the Japanese bombers and short of fuel, Vice Admiral Frank Jack Fletcher asked on 8 August to withdraw his three carriers, and the theater commander, Vice Admiral Robert Ghormley, agreed. Rear Admiral Richmond Kelly Turner then decided he could not keep his transports off the beaches without air cover and took them away the next day, with more than half of the division's supplies still in their holds. Morison judged Fletcher's reasons for leaving flimsy.⁸

Major General Alexander Vandegrift was left ashore with his 1st Marine Division. He dug in around the airfield on Lunga Point, used the Japanese engineers' abandoned equipment, and fed his men for a time on captured Japanese rice.⁹

The Japanese command at first took the landing for a raid and fed its troops in by installments. The first to arrive was the detachment of Colonel Kiyono Ichiki, which had been meant for Midway. Ichiki landed with an advance echelon of about 1,000 men and, once his force had been discovered, attacked without waiting for the rest. Each later attempt, by Major General Kiyotake Kawaguchi's brigade in September and by the 2nd Division of Lieutenant General Masao Maruyama in October, was larger, but none came with all the strength Japan could have gathered at once.¹⁰

Holding Henderson Field

The Japanese poured in troops to retake the field, and the Marines fought off repeated assaults through the jungle, including desperate night battles along the ridges and the Matanikau River. The aircraft flying from Henderson Field, known as the Cactus Air Force from the island's code name, gave the Allies control of the skies by day.¹¹

What were the main battles of the Guadalcanal campaign?

On land, the Marines and later the Army defeated three major Japanese attempts to retake Henderson Field: at the Tenaru in August, on Edson's, or Bloody, Ridge in September and in the October battle for the airfield. At sea, the two navies fought a series of major battles, beginning with Savo Island in August and ending with the Naval Battle of Guadalcanal in November.¹²

At the Tenaru River on 21 August the Ichiki detachment attacked the Marine line and was almost wiped out. The Army history counts nearly 800 Japanese killed and only 130 survivors; Morison writes of almost a thousand dead; the National Archives gives 789 of 917. The Marines lost 35 killed and 75 wounded, and Ichiki took his own life.¹³

On 12 to 14 September Kawaguchi's brigade struck the ridge south of the airfield, held by Marine Raiders and Parachutists under Lieutenant Colonel Merritt Edson. Of some 2,000 Japanese who attacked the ridge, about 600 fell there, by the count of both the Army and the Navy histories, and the National WWII Museum gives the attackers more than 700 casualties. Marine losses were 31 killed, 103 wounded and 9 missing in the Army's count, 40 dead and 103 wounded in Morison's.¹⁴

The largest attack came from 23 to 26 October, when the Japanese 17th Army assaulted the perimeter at several points night after night and lost thousands of men. On the night of 24 October Sergeant John Basilone kept his machine guns firing through the assault, an action that earned him the Medal of Honor.¹⁵

At sea the fighting followed the reinforcement convoys: the Eastern Solomons on 24 August, Cape Esperance on 11 to 12 October and the Santa Cruz Islands on 26 October, where Japan sank the carrier Hornet but lost many of its trained aircrew. In the Naval Battle of Guadalcanal, 12 to 15 November, American ships and aircraft turned back Japan's last attempt to knock out Henderson Field from the sea. A captured Japanese document, quoted by Morison, called the struggle for the island and the sea battle around it “the fork in the road” that would lead to victory for one side or the other; the National WWII Museum attributes the phrase to a Japanese officer.¹⁶

The battles at sea

Around the island the two navies fought a series of ferocious night actions in the waters that sailors soon nicknamed Ironbottom Sound for the ships sunk there. Both sides lost heavily, including carriers and cruisers, as each tried to land reinforcements and cut off the other.¹⁷

Attrition and withdrawal

Unable to feed and supply its troops against Allied air and sea power, Japan lost thousands to combat, disease and starvation. In early February 1943 the Japanese quietly evacuated their surviving soldiers, and the campaign ended in Allied victory.¹⁸

Command on the American side changed as the campaign went on. On 18 October the aggressive Vice Admiral William Halsey replaced Ghormley as commander in the South Pacific, and in December Army divisions began relieving the worn-out 1st Marine Division. Under Major General Alexander Patch, the XIV Corps pushed west along the coast in January 1943.¹⁹

By then Japan had decided to give up the island. Imperial General Headquarters canceled a planned counteroffensive on 31 December, and on 4 January 1943 the order went out to evacuate Guadalcanal within a month; Morison notes that it was passed only to the top commanders while the troops fought on. In three night runs, on 1 to 2, 4 to 5 and 7 to 8 February, destroyers carried the survivors away from Cape Esperance: 11,706 men by Morison's count, about 13,000 by the Japanese figure given in the Army history.²⁰

How many men died at Guadalcanal?

Figures vary with what is counted. Of about 60,000 Army and Marine ground troops committed to the island, about 1,600 were killed in action and 4,245 wounded, according to the Army's official history; Morison gives 1,592 killed in action and adds that the Navy's losses, never compiled, were certainly higher. Of the more than 36,000 Japanese who fought on Guadalcanal, both histories count over 14,800 killed or missing, 9,000 dead of disease and about 1,000 taken prisoner.²¹

Counting the battles at sea and in the air, the National WWII Museum gives losses of about 7,100 Allied and 31,000 Japanese men, with 29 Allied ships and 615 aircraft lost against 38 Japanese ships and 683 aircraft. Morison's table of combat ships, which leaves out transports, comes out even: 24 on each side, among them two American carriers and two Japanese battleships.²²

Why did Japan lose Guadalcanal?

Japan lost because it could not keep its army on the island supplied. Aircraft from Henderson Field controlled the surrounding waters by day, so reinforcements came in piecemeal by night on fast destroyers, never enough to win, while the troops ashore went hungry and fell sick and American strength grew with every convoy.²³

The cost at sea and in the air mattered as much as the fight on land. Japan lost over 600 aircraft with their pilots, the Army history notes, a loss that would hinder its later operations. The historian Jonathan Parshall goes further and argues that the fighting around Guadalcanal did more damage to the Japanese navy than Midway, destroying much of its cruiser and destroyer force and the last of its elite naval aviators.²⁴

Why Guadalcanal mattered

Guadalcanal took the strategic initiative from Japan and was the point at which the Pacific war turned: from here the Allies advanced and Japan was on the defensive. The Army history concludes that the offensive halted the Japanese advance toward the line of communications between the United States and Australia. See also the Battle of Midway and the Battle of Okinawa.²⁵

Guadalcanal was also the first step toward Rabaul, the great Japanese base on New Britain, which the Allies set out to reduce by advancing through the Solomons and New Guinea. Morison calls the campaign Task One in the arduous climb to Rabaul, and the Army history describes it the same way. From there the long advance led on across the Pacific, to Tarawa and beyond.²⁶

How is Guadalcanal remembered today?

The campaign made heroes of the men who fought it. John Basilone, the machine gunner of the October battle, received the Medal of Honor and was later killed in action on Iwo Jima in February 1945.²⁷

For the Navy the island's memory is written in the name of the sound off its northern shore. The sailors called it Ironbottom Sound because of the dozens of ships of both navies that lie on its floor, and the name has stuck ever since.²⁸