Buna-Guna

Following the United States' entry into World War II in December 1941, Martin was promoted to the temporary rank of Colonel and joined the headquarters of I Corps as Assistant Chief of Staff for operations (G-3). He served consecutively under Major generals Charles F. Thompson and Robert L. Eichelberger and accompanied his command overseas, arriving to Brisbane, Australia in mid-September 1942. The First Corps consisted of two inexpirenced National Guard Divisions – 32nd and 41st and Supreme Commander of the Southwest Pacific Area, General Douglas MacArthur, ordered Eichelberger to deploy 32nd Division to New Guinea to help Australians to stop Japanese in capturing of Port Moresby.^[2][3]

Although the 32nd Division did not completed its training, MacArthur ordered its deployment to New Guinea by the end of September 1942. The 32nd Division soon began struggling in combat with Japanese and after a month of fighting at Buna–Gona, Eichelberger flown his staff to Buna-Gona to have better situational overview on December 1, 1942. After a conference with 32nd Division Commander, Edwin F. Harding, Eichelberger dispatched Martin and Corps' Intelligence Officer, Gordon B. Rogers to assess the situation.^[3][4]

Martin and Rogers were ordered to inspect Warren Force, a task force made up of Australian and American forces, and they had to travel on foot due to weather conditions and dense jungle. Once they arrived on the frontline, they found units of Warren Force in defensive positions with little fighting ongoing. Martin and Rogers returned to the divisional headquarters at Dobodura in late night and were highly critical of Warren Force performance. Eichelberger subsequently decorated Martin with Silver Star for bravery in action for conduction hazardous mission for gathering of important information.^[3][4]

Eichelberger relieved Harding and all regimental commanders for lack of aggresivness and progress on December 3, 1942, and Martin was chosen as Commanding officer of division's 128th Infantry Regiment, relieving Colonel J. Tracy Hale. He was also given additional duty as Commanding officer of Warren Force and began with the reorganization of his unit.^[2][3][4]

Following an airstrike of six A-20's, and a brief artillery preparation, Martin led his task force in attack against Japanese positions on December 5, but well organized enemy units repelled Warren Force. Martin and his unit then remained at the positions until Christmas Day of 1942 and then resumed their attack in early morning. However Warren Force's advance was soon halted by strong Japanese resistance and Martin sent a detachment from his regiment for reconnaissance of nearby swamp are to find a way around the enemy's right flank. Upon receiving report that the swamp was impenetrable, Martin decided to personally explore the area to find a way through. He finally find a way through and the detachment was able to penetrate into the enemy's rear, but Martin wasn't able to get reinforcements over there until after dark.^[3][4]

After the reinforcements has arrived, Martin decided to climb a tall tree that overlooked the Japanese positions to get a better view on enemy troops lurking in the tall grass immediately to his front. From this vantage point he killed several of them with a rifle. Warren Force then participated in the bitter fighting against fanatical Japanese resistance until the end of January 1943, when Buna was declared secured. For his service on Buna-Guna, Martin received Distinguished Service Cross, the second highest military decorations of the United States for bravery in combat. He also received the Combat Infantryman Badge, an honor he was most proud of.^[5][1][3][4]

Saidor

Martin (center) observes the landing at Saidor with Rear Admiral Daniel E. Barbey, and Brigadier Ronald Hopkins.

Due to his leadership abilities and personal bravery, Martin was promoted to the rank of Brigadier general on February 3, 1942, and joined the headquarters of 32nd Infantry Division as Assistant Division Commander and Deputy to Major general William H. Gill. He accompanied the division back to Brisbane, Australia, where he supervised the re-equipment and retraining of the Division for next campaigns in South Pacific which took more than six months.^[2][6]

The 32nd Division moved back to New Guinea in mid-October 1943 and continued their amphibious training at Milne Bay and Goodenough Island until January 1944, when received orders to deploy in the mainland of New Guinea. Its goal was to take part in the Landing at Saidor, a village on the north coast of Papua New Guinea. The Division was selected by Generals MacArthur and Walter Krueger (Commanding General, Sixth Army) and its primary objective was the capture of the airstrip at Saidor which will allow construction of an airbase to assist Allied air forces to conduct operations against Japanese bases at Wewak and Hollandia. Secondary objective was to cut off the 6,000 Imperial Japanese troops retreating from Sio in the face of the Australian advance from Finschhafen. Martin took part in the planning of the assault and was selected by Gill to lead a Michaelmas task force, which was built around the 126th Infantry Regimental Combat Team with Colonel Joseph S. Bradley in command.^[7][6]

The main landing on dawn of January 2, 1944, found little opposition from Japanese and Martin and his task force encountered only occasional aggressive Japanese patrols in upcoming days. The mission of capturing the airfield area had been quickly accomplished and by the afternoon of January 4, 1,800 ft (550 m) of runway was ready for use. Another engineer units improved the airstrip, permitting twelve C-47 Skytrains loaded with ammunition to land on January 11, 1944.^[6]

On January 12, Martin received intelligence reports from Sixth Army headquarters that the Japanese were concentrating around Sio, and would attempt to force their way through to Madang. In response to a request from Martin for reinforcements, the 1st and 3rd Battalion Combat Teams of the 128th Infantry Regiment were sent to reinforce Saidor, arriving on January 16. Martin came to believe that an advance to the east and an attack on the withdrawing enemy would "provide an opportunity to destroy the Japanese before they could organise an attack on the Saidor position".^[6]

General Walter Krueger did not immediately give Martin permission for such an operation. There was still the possibility of Japanese attack, and the 32nd Infantry Division was required for the upcoming Hansa Bay operation. On January 20, a visiting staff officer from Sixth Army was asked to raise the possibility with Krueger. However, on January 21, 1944, Martin received a letter stating that the mission of his Task Force remained unchanged and a radiogram was received on January 22 to the effect that this was not consistent with Krueger's wishes. On February 8, Martin received a garbled radiogram from Krueger that indicated that the earlier restrictive message of January 22 had itself been garbled, and on February 9, a radiogram was received authorising offensive action. Plans were immediately made but on February 10 contact was made with elements of the Australian 5th Division, which had relieved the 9th Division on January 20. This closed the gap on the east flank.^[6]

Although the intensity of clashes with the Japanese increased, over 8,000 enemy soldiers were able to bypassed Martin and his task force due to late orders from Krueger. The Japanese lost approximately 1,000 men while U.S. forces had 67 casualties including killed in action, wounded and missing and Krueger considered the campaign successful despite the secondary goal of cutting off the Japanese forces from their lines was not fulfilled. For his service in New Guinea, Martin was decorated with Legion of Merit and also received Distinguished Service Order by Australia.^[1][6]

Aitape

Martin (center) with his division commander, MG William H. Gill (right) and Division Artillery commander BG Robert B. McBride during the field briefing at New Guinea in summer of 1944.

In April 1944, the 32nd Division was selected again by MacArthur and Krueger to took part in the Landing at Aitape to isolate the Japanese 18th Army at Wewak. After two weeks of fighting, Aitape was secured with 550 casualties on the Japanese side in contrast to 60 Allied casualties. However the retreating 20,000 men of Japanese 18th Army were about to attack Aitape and General Gill prepared, together with Martin, a defensive plan and ordered his division to dig in. Gill then placed Martin in charge of Covering force, which was sent for a reconnaissance mission and was tasked with the delaying of the enemy on Driniumor River, before U.S. forces can prepare all of its forces for counterattack.^[8][7][9]

Due to difficult terrain and weather conditions, the supplying of Martin's was slow and he had a force of roughly 1,500 men to cover a frontage originally designed for two to three times that number. When Japanese launched their attack during the night of July 10, 1944, Martin led the withdrawal of his task force following some planned delaying actions and Japanese forces were able to break through the first line of defence. General Krueger refused to believe that Martin's retreat from the Driniumor River had been necessary and did not agree with Martin's estimate of the seriousness of the situation.^[8][9]

On July 12, Martin was replaced in command of Covering force by General Gill and was assigned to command of Eastern Sector of Driniumor River. He also retained his duty as Assistant Division Commander, 32nd Infantry Division under Gill. Although Martin became the scapegoat for failing to prevent the Japanese breakthrough he remained with his division until the end of campaign which resulted in almost 10,000 dead Japanese with 440 Killed in Action on the Allied side by the end of August 1944.^[8][9]

Morotai

Martin (center) over the map with 31st Division's Assistant commander BG Joseph C. Hutchinson (left) and division's artillery commander BG Thomas F. Hickey (right) in Pacific in late 1944.

In mid-September 1944, Martin was tasked by Gill to lead a Regimental combat team during the landing on Morotai, an island in the Dutch East Indies intended to be used as a base to support the planned liberation of the Philippines later that year. The invading forces greatly outnumbered the island's Japanese defenders and secured their objectives in two weeks. Martin's abilities as potential Division commander were recognized and he was appointed Commanding General, 31st Infantry Division ("Dixie") on September 23 with the temporary promotion to Major general.^[1][2][10]

The 31st Division was composed chiefly of Southerners from Alabama, Florida, Louisiana, and Mississippi and saw only limited action against Japanese arriving to the South-West Pacific Area in late April 1944. It was stationed on Morotai following the main landing and seized Mapia, on November 15–17, and waded ashore on the Asia Islands, November 19–20, only to find the Japanese had already evacuated. Martin supervised the division's training for the upcoming liberation of the Philippines and successfully conducted base operations both in Sansapor and Morotai.^[1]

Mindanao

Martin and his division landed on Mindanao on April 22, 1945, and together with the Philippine Commonwealth Army and Philippine Constabulary they fought the Japanese forces along the Sayre Highway and driving down the Kibawe-Talomo trail. After the Japanese withdrawal into the interior, the 31st Division blocked off other Japanese in the Davao area and destroyed the enemy in the Bukidnon Province and Agusan Valley.^[1][7]

Following the arrival of Japanese reinforcements from the disintegrated 35th Army, Martin led combats along the Agusan River and in the jungles around Waloe until the cessation of hostilities on August 15, 1945. His division was subsequently tasked with accomplishing the surrender of all Japanese forces on Mindanao. Martin's division secured the Agusan Valley, Bukidnon Province, Davao and Sarangani Bay areas, securing 22,310 prisoners-of-war. The 31st Division was then responsible for the evacuation of the Japanese personnel back to Japan until the end of October, when they were ordered to embark for the United States. For his service on Mindanao, Martin was decorated with the Army Distinguished Service Medal. He also received the Air Medal for participation in the aerial reconnaissance over Mindanao.^[11][1][12]