Japan inked the Tripartite Pack with Italy and Germany in September 1940 to get engaged officially in World War 2 and become a part of the Axis Powers.
Under the treaty, the three aggressive nations agreed to offer military aid to one another in case of any attack launched on them by a nations that has not yet engaged itself in the war.
In the same month, Japan launched an attack for occupying French Indochina and the US, which was not playing a proactive role in the War retaliated by imposing economic sanctions, with an embargo on steel and oil.
Japan instigated a raucous attack on American, Dutch and British controlled territories along the Asia Pacific region in December 1941.
Japanese fighter planes bombarded Pearl Harbor, the US naval base situated near Honolulu, Hawaii Island.
The ghastly attack claimed the life of nearly 2,500 mariners and also destroyed or damaged 18 ships and the US reciprocated by declaring war on Japan a day after the Pearl Harbor bombing.
Japanese invasions encompassed a cosmic area of western Asia-Pacific and south-east Asia by June 1942.
The prisoners of war and captivated civilians under Japanese occupied territories were subjected to inhuman tortures violating the Geneva Convention and forced to toil hard for their subjugators under adverse conditions and ambiance, which has been brilliantly depicted in Academy Award winning movie Bridge on the River Kawai, directed by David Lean.
Over the next seven month period, Japan expanded its wings by occupying Philippines, South Korea, Burma (Myanmar), British Singapore, New Guinea and the Dutch West Indies along with several other territories in Asia-Pacific and Southeast Asia.
However, the fortune of the Axis powers started reversing from June 1942 during the Battles of Midway and Guadalcanal and a series of bomb-raid allover Japan.
By mid of 1944, the Japanese army led by General Hideki Tojo realized that victory was implausible but did not stop its assaults on the Anti-Axis forces until the US dropped two atom bombs, first at Hiroshima on August 6, 1945 and then at Nagasaki on August 9, 1945, forcing Japan to admit defeat.
In a radio broadcast on August 15, 1945, Japanese Emperor Hirohito announced the unconditional surrender of his country to the US-led Alied Forces.
Japan signed the instrument of surrender on September 2, 1945, thereby officially ending World War 2.