The recovery of the territories conquered by Japan in 1941/42 took place very slowly against the stiff resistance of the Japanese island garrisons and with the greatest willingness of the Japanese soldiers ( kamikaze) to make sacrifices, although in 1943 about half of the American armed forces were deployed in the Pacific.
On August 7, 1942, according to EBIZDIR,the American forces landed on the Solomon island of Guadalcanal, which became the scene of a month-long attrition battle; The Japanese did not give up until February 8, 1943. In the central Pacific, the American forces under C. Nimitz advanced towards the Mariana Islands, in the southwest Pacific the forces under D. MacArthur advanced through New Guinea towards the Philippines.
In order to restore the land connection with China (Chiang Kai-shek), the British sought to regain Burma. From there the Japanese tried for their part on February 4, 1944 with the help of the Indian national army S. C. Bose to advance to Assam, but got stuck shortly after the border. On April 17, 1944, the Japanese army began a major offensive in China to establish a land connection with Indochina. The conquest of the Mariana Island of Saipan by the Americans (June 15 – July 9, 1944) led to the resignation of the Japanese War Cabinet under Tōjō Hideki.
On October 20, 1944, MacArthur opened the reconquest of the Philippines with the landing on Leyte Island. In the sea battle near the Philippines (October 23-26, 1944), the Japanese lost four aircraft carriers and three battleships and thus the core of their fleet. Manila was reclaimed on February 23, 1945 and the rocky island of Corregidor on February 28. From November 1944, the American armed forces carried out heavy air raids on Tokyo and other Japanese cities from Saipan and Guam. On April 1, 1945, they landed on the Ryūkyū Island of Okinawa. It was taken until June 21st after very hard fighting. This pushed the American air bases close to the Japanese motherland. The British (Lord Mountbatten) had recaptured Burma from March 1945 and on May 3, 1945 had advanced into Rangoon, which had been evacuated by the Japanese; this opened the way to Singapore and Thailand.
On April 5, 1945, the Soviet government terminated the neutrality treaty with Japan. It negated all Japanese requests to broker a peace with the United States. The response of the Japanese government to the request of the Potsdam Conference of July 26, 1945 to surrender unconditionally was declared by the Allies to be inadequate. On August 6, 1945, the USA dropped the first atomic bomb on Hiroshima (80% destruction of the city) in order to achieve a faster end to the Pacific War and the final surrender of Japan.
Whether and to what extent other reasons also played a role in the decision, e.g. For example, a show of force against the Soviet ally or consideration for the enormous costs incurred in developing and manufacturing the bomb are still controversial today. In fact, at this point the Japanese were already ready to surrender. On August 8, the USSR declared war on Japan and sent its troops into Manchuria the following day, the day the US dropped a second atomic bomb on Nagasaki. On August 10, the Japanese government announced its readiness to surrender to the United States, with the proviso that the privileges of Emperor Hirohito should not be impaired.
In its response, the United States announced the decision to place the Emperor and the Japanese government under a high command of the Allied forces. On August 15, the emperor ordered all Japanese armed forces to stop fighting immediately. The advance of the Red Army continued regardless. On August 22nd, Port Arthur and Dairen were occupied, other Soviet troops landed on the Kuril Islands and advanced into North Korea. On August 30, 1945, the Japanese surrendered Hong Kong to the British again.
On September 2, 1945, the surrender of Japan on the American battleship Missouri was signed in Tokyo Bay. On September 9th, the Japanese army in China also surrendered in Nanking (Nanjing). The disarmament of the Japanese troops ended on October 24, 1945. The main Japanese island and South Korea were occupied by the USA. The American General MacArthur took control of Japan.
On August 14, 1945, the Chiang Kai-shek government, returning from Chongqing to Nanking, had to accept the restrictions on sovereignty granted by Roosevelt in Yalta to Stalin in a “friendship treaty” with the USSR. Substantial parts of northern China were taken by the communist forces of Mao Zedong, which had previously been part of the national united front against the Japanese.