During the Battle of Bougainville in the Pacific War, a Japanese soldier was killed by American troops while holding a gas mask. The bodies of the slain Japanese soldiers fell and were scattered in the jungle.

  During the Battle of Bougainville in the Pacific War, a Japanese soldier was killed by American troops while holding a gas mask. The bodies of the slain Japanese soldiers lay scattered in the jungle.

  The Battle of Bougainville Island between Allied and Japanese forces broke out on November 1, 1943, and ended on August 21, 1945. Bougainville Island is the largest island in the Solomon Islands at about 10,000 square kilometers. The Japanese forces established the headquarters of the Seventeenth Army, which withdrew from Guadalcanal Island. Its troops included the 6th Division, the 17th Infantry Corps, and the 4th South Sea Garrison, which was eventually garrisoned by about 60,000 to 80,000 men.   

　On October 27, 1943, New Zealand troops landed on Mono Island (Treasury Island) and mopped up about 200 Japanese naval land forces; on October 27, American troops landed on Choiseul Island and, after a battle with about 1,000-plus Japanese garrison troops on the island, withdrew on November 4; on November 1, Allied On November 1, the 3rd Marine Division of the Allied Forces landed from Tarokina Beach on Bougainville Island. The Japanese naval air force at Rabaul launched a sortie and attacked American warships near Tarokina beach in the Battle of Bougainville Island. The Japanese 23rd Infantry Regiment, stationed at Mosigeta, closest to the landing point, invaded Tarokina Beach with about 2,200 men, and fighting broke out on November 8. Encountering the firepower of the U.S. forces, which had a disparity of about 150 to 1, the commander of the Japanese regiment, Toshiaki Hamanoue, who judged that it would be more like a massacre than a battle, retreated on his own initiative.

   After the 23rd Infantry Regiment of the Japanese Army had withdrawn from the offensive against the landing forces on the Tarokina coast, the Japanese Army's 17th Army concentrated its forces and prepared to resume the offensive. Just then, the Japanese Army's Eighth Area Army on Rabaul was instructed by the Imperial Japanese Army headquarters to postpone the offensive. Although the Imperial Japanese Army and the Navy hoped for an early attack, the Eighth Area Army pushed through with the postponement, saying that unless the attack concentrated sufficient forces, it would be ineffective under the current circumstances in which the Allied Forces held both air and sea control. The commander of the Japanese 23rd Regiment, which withdrew on the third day of the attack, was wounded and removed from his post. At one point, there was a strong opinion in the 8th Area Army that the commander of the 23rd Regiment should be court-martialed for fleeing before the enemy. If they stayed and continued the attack, they were expected to be crushed to pieces and wiped out early, so it was natural for the Japanese to temporarily halt the offensive of the area forces.

  The 6th Division of the Japanese Army was located more than a hundred kilometers from the Buin area, while the 45th Regiment, which was one wing of the Japanese Army, was positioned on the opposite side, in Kieta, on the opposite side of the Tarokina coast in the jungle-covered mountains. On March 8, 1944, the Seventeenth Army launched a general offensive. The invasion took a long time, cutting through steep jungle. The opposing Allied forces numbered about 62,000 in the Fourteenth Army, of which the first line consisted of the 3rd Marine Division and the Americal Division, totaling about 27,000 men. The Japanese forces fought valiantly to defend themselves under constant bombardment, but were forced to withdraw at the end of March 1944. The casualties of the Battle of Bougainville Island ranged from 20,000 to 30,000 Japanese, most of whom died of starvation or disease, while approximately 1,243 Americans were killed in action. The Japanese forces were without food, arms, or ammunition for about two years until the end of the war, and many of their troops, abandoned by their country, were wiped out.