In December 1941 Japan, already at war with China, attacked British, Dutch and American territories in Asia and the Pacific. By June 1942, Japanese conquests encompassed a vast area of south-east Asia and the western Pacific. Under Japanese occupation, prisoners of war and enslaved civilians were forced to work for their captors in harsh and often inhuman conditions.

A series of land battles were fought in China, Burma and New Guinea. Although Japan achieved early successes, its resources were overstretched. In contrast, America was able to mobilise huge economic resources to intensify its efforts, beginning with amphibious landings in the Pacific. Tokyo and other Japanese cities suffered unprecedented destruction by conventional bombing. Finally, after atomic bombs were dropped on Hiroshima and Nagasaki, and following Soviet intervention, Japan surrendered in August 1945.

Japanese occupation hastened the end of European colonialism and the rise of communism in Asia, while post-war American occupation transformed Japanese society.

Japan's role in the Second World War

From Pearl Harbor and the development of atomic bombs, Hiroshima and Nagasaki, VJ and VE Day and the events that followed summer 1945, below is a collection of stories mapping out milestones in Japan's role in the Second World War.  

Japan at War

Emperor Hirohito superimposed on a map showing the oil fields in the Dutch East Indies which Japan targeted.
Second World War

Why did Japan attack Pearl Harbor?

Japan attacked the U.S Pacific Fleet on the 7th of December 1941, but what led to that decision? Why did the Japanese attack the USA? - The answer is oil. In this episode of IWM Stories, Adrian Kerrison looks at why the Japanese decided to attack Pearl Harbor.

Kanohoe naval air station, strewn with damaged aircraft and wreckage, 7 December 1941. In the background an explosion sends a ball of flame into the air.
Second World War

What Happened At Pearl Harbor?

On the morning of 7 December 1941, at 7.55am local time, 183 aircraft of the Imperial Japanese Navy attacked the United States Naval base at Pearl Harbor on the island of Oahu, Hawaii.

Three Grumman Avengers flying over the battleship HMS KING GEORGE V and other units of the British Pacific Fleet when on the way to attack Sakishima targets in support of the American landing on Okinawa.
© IWM A 29174
Second World War

A Short History Of The War In The Pacific During The Second World War

On 7 December 1941, Japan launched a surprise air attack on the US naval base at Pearl Harbor in Hawaii. Japanese forces also overran Allied possessions in south-east Asia and The Philippines. Japan hoped for a short war, seeking to quickly weaken US naval strength and capture strategically vital oil supplies. But what happened next?

Still from footage of the Yokosuka MXY-7 Ohka - the only jet-powered suicide aircraft, suspended from the ceiling of IWM London.
Second World War

How effective was the Japanese kamikaze campaign?

In the later stages of the Second World War in the Pacific, Japan was desperate. They turned to a new tactic - kamikaze. The kamikaze campaign trained attack squadrons specifically for this purpose, and brought into combat a new aircraft - the Yokosuka MXY-7 Ohka - the only jet-powered suicide aircraft.

They first saw action at the Battle of Okinawa in 1945, where extensive damage was done to the Allied fleet. But overall, how effective were these aircraft and this campaign?

A map of the Japanese attack on Singapore with British general Percival superimposed. The text reads: "Britain's biggest defeat".
Second World War

Why did Singapore fall?

On the 15th of February 1942, Lt General Arthur Percival signed the largest surrender in British history at Singapore. The city was supposed to be a fortress, but his force of 85,000 men had been defeated by just 35,000 Japanese troops. So how did the Japanese defeat a numerically superior force? Why wasn’t Singapore an impregnable fortress? And could the British have held out?

Top view of American aircraft attacking the Japanese Fleet. Three Japanese carriers circle below with red X’s on them, the silhouettes of American dive bombers close in.
© Public Domain - Naval History and Heritage Command
Second World War

Why Japan lost the Battle of Midway

The Battle of Midway was a pivotal naval battle that began on 3 June 1942 and dramatically changed the course of the war in the Pacific. Join IWM curator Adrian Kerrison at IWM Duxford to find out more about the timeline of events that lead to the Battle of Midway and the crucial decisions leading to Japan's defeat.

Burmese civilians pulling a cart during the evacuation of Rangoon, 1942.
© IWM JAR 1230
Second World War

Listen To 8 People Describe The War In Burma In Their Own Words

In January 1942, the Japanese Army invaded Burma (now called Myanmar). Allied troops endured over three years of brutal fighting, often in extreme terrain and menaced by severe weather and the threat of disease. Allied troops, led by Britain's Indian Army, reoccupied Burma in 1945. Listen to 8 people describe their experiences of the Burma Campaign during the Second World War.

The interior of a wooden hut with two large windows behind giving onto sunlit green foliage. In the centre of the floor is a tin bath full of water. On the right two women talk. Beyond them another woman supervises a child washing. Seven girls can be seen around the room at various activities and a lone baby sits on the floor. Lines of white washing are spread across the bunks. The women and children are severely emaciated.
Second World War

A Short History Of Civilian Internment Camps In The Far East

Over 130,000 Allied civilians - 50,000 men, 42,000 women and 40,000 children - were interned in the Far East during the Second World War. The majority of them were Dutch nationals from the Netherlands East Indies.

Second World War

What You Need to Know About the Battle of Okinawa

The Battle of Okinawa was the brutal final chapter in the fighting of the Pacific War. It was a battle that saw such horrific casualties - both military and civilian -  that it forced the United States to look for alternatives to an invasion of Japan to bring the war to an end. 

Atomic Bombs

A bomb thumbnail
Second World War

Why were Atomic Bombs Dropped on Hiroshima and Nagasaki?

The bombing of Hiroshima and Nagasaki in August 1945 brought an end to the Second World War, but at a terrible cost to the Japanese civilian population, and signalling the dawn of the nuclear age. What had led to the fateful decision to deploy these new weapons of mass destruction?

Photograph depicting the aftermath of the Atomic Bomb in Hiroshima.
© IWM MH 29447
Second World War

Voices of War: Hiroshima

Listen to our soundscape and reflect on what happened when the atomic bomb was dropped on Hiroshima on 6 August 1945. 

Second World War

Voices of War: Nagasaki

On 9 August 1945, an atomic bomb was dropped on the Japanese city of Nagasaki. Listen to first-hand accounts of what happened in Nagasaki, taken from IWM’s extensive sound archive and the archives of the Atomic Heritage Foundation.

Hiroshima following the dropping of the atomic bomb on 6 August 1945. The prominent building in the foreground was the Industry Promotional Hall, retained in its ruined state as a peace memorial.
© IWM MH 29427
Second World War

The Atomic Bombs That Ended the Second World War

The end of the Second World War witnessed the emergence of a new weapon. How did the Allies make the decision to drop two atomic bombs on Japan in August 1945? 

The aftermath

Okinawa Battle © IWM A 29192
© IWM NYF 70677
Second World War

The Proposed Invasion of Japan

On 8 May 1945, the Allies celebrated VE Day, marking the end of the war in Europe. But the war in the east still raged on and Japanese surrender seemed a long way off. What did the proposed invasion of Japan look like? 

Civilians and service personnel in London's Picadilly Circus celebrate the news of Allied Victory over Japan in August 1945. © IWM D 25636
Second World War

Voices of War: VJ Day

75 years ago, the Second World War came to an end and was marked by the Allied nations on VJ Day. Listen to the voices of some of those who were there and discover what it meant to them.

Polish nationals waiting for the arrival of army lorries to take them from No.17 Displaced Persons Assembly Centre in Hamburg Zoological Gardens to a Polish national camp for repatriation. © IWM BU 6641
© IWM BU 6641
Second World War

VJ Day and the End of the Second World War

What did the end of the Second World War mean to people whose lives had been touched by the conflict? 

Victory parade in Berlin, July 1945. Mr Churchill about to set off in brake to inspect troops before Victory parade in Charlottenburgerchausee.
© IWM A 30121
Second World War

Beyond VE Day: The Events of Summer 1945

The photographs of smiling faces on VE Day conceal the challenges and struggles that still lay ahead in 1945.

The Battle of Singapore, February 1942.
© IWM HU 2781
Second World War

Britain and Decolonisation in South East and South Asia, 1945-1948

Victory over Japan Day marked the end of the Second World War in August 1945. Yet the conflict did not end on this day, particularly in Asia. While decolonisation across South and South East Asia seemed inevitable, the territory of the British Empire was at its apogee in 1945 and the journey to independence for countries in this region was not simple.