Japan campaign


The Japan campaign was a series of battles and engagements fought in and around the Japanese home islands, between Allied forces and the forces of Imperial Japan during the last stages of the Pacific campaign of World War II. The Japan campaign lasted from around June 1944 to the end of the Pacific War in August 1945.

Air war

Periodic air raids on Japan were the first attacks undertaken by Allied forces against the Japanese mainland. In late 1944, these raids were followed by a major strategic bombing against cities, factories, and other war infrastructure throughout Japan, most notably:
These air raids caused heavy damage to Japanese infrastructure and domestic industry, the deaths of 241,000–900,000 Japanese citizens, and the loss thousands of aircraft and flak guns. The Allies, in turn, only lost a few hundred aircraft to Japanese anti-air defenses and fighters.
From March 1945 until the end of the war, the US Navy's Fast Carrier Task Force began operating in close proximity to the Japanese mainland with increasing impunity. American carrier aircraft continually struck Japanese airfields and dockyards for over five months, in a series of air raids that the Japanese contested with decreasing frequency.

Land and sea battles

In early 1945, there were two major island battles fought as part of the Japan campaign:
There were also two naval battles:
  • Operation Ten-Go : All but four Japanese vessels committed were sunk by American carrier aircraft.
  • The Battle of Tokyo Bay : Most of the Japanese vessels committed were heavily damaged or lost.
Allied warships also bombarded several Japanese cities during July and August 1945.
Fierce fighting during the battles of Iwo Jima and Okinawa generated a grim outlook for the eventual amphibious landings on the Japanese Home Islands among Allied strategists. Japanese ground troops had fought effective campaigns of attrition on both islands, and Allied naval forces were subjected to massed kamikaze attacks throughout the battle of Okinawa. In both cases, the Japanese refused to surrender and there were few survivors. While Japanese losses were near-complete, Allied forces also incurred tens of thousands of casualties during the fighting.
Naval operations of the Japan campaign included a suicidal Japanese counteroffensive on 7 April 1945, tasked with the insurmountable objective of relieving Okinawa, as well as an Allied campaign to place air and submarine-delivered mines in Japanese shipping lanes. This was illustrated by the naval surface engagement at Tokyo Bay in July 1945.
In late 1945, the Soviet Union launched a series of successful offensives against several northern Japanese territories, in preparation for a possible invasion of Hokkaido:
ended with the surrender of Japan after the atomic bombings of Hiroshima and Nagasaki and the Soviet invasion of Manchuria. The firebombing of Japanese cities resulted in some 350,000 civilian deaths and devastated Japanese cities, but did not meaningfully push the Japanese government towards surrender. While offering lukewarm indications that it was prepared for peace talks, the Japanese government had also made preparations to contest an Allied invasion of the home islands as fiercely as they had defended Iwo Jima and Okinawa, including plans to carry out a protracted guerrilla campaign and carry out massed kamikaze strikes against Allied naval forces.
The intended purpose of the Japan campaign was to provide staging areas and preparation for a possible Allied invasion of Japan, support Allied air and naval operations against the Japanese mainland and further isolate Japan from its remaining overseas possessions. However, although the remaining vessels of the Imperial Japanese Navy had been largely sunk or immobilized and Japanese air units no longer contest Allied command of the skies by June-July 1945, Japan still maintained significant ground forces on the home islands.
Allied strategists judged that an amphibious invasion of the home islands would likely result in extremely heavy casualties. By July 1945, Japanese forces on the home islands had grown to nearly two million men, organized into units of varying quality and type, amounting to over 800,000 men on Kyushu alone. Japanese males aged 15-60 and women aged 17-40 were drafted into civilian militias, whose enlistment roles officially topped 25 million, and were often equipped only with spears or household weapons. Although Japan had ceded air superiority to the Allies, it maintained a reserve of some 9,000 aircraft, intended to be utilized as kamikazes during the impending Allied invasion. Japanese units had standing orders to engage in protracted guerrilla warfare should they be overrun.
By June 1945, the American military leadership had decided to continue and intensify the naval blockade and aerial bombardment of the home islands, hoping to compel a Japanese surrender prior to the planned invasion of Kyushu in November 1945. If the Japanese still refused to surrender after Allied forces invaded Kyushu, additional landings were planned on Honshu to seize Tokyo in early 1946.
Japan surrendered in August 1945, preventing these landings from taking place. Japan's surrender is attributed to a mixture of factors, including the atomic bombings of Hiroshima and Nagasaki, the strategic bombing of Japanese cities, the tightening naval blockade of the home islands, and the Soviet invasion of Manchuria.