<h2>Answer:</h2>
Before August 1945, military leaders in Japan remained continuously in war In world war 1 Japan stood by Great Britain. Attended the peace settlement at Versailles and recognized as one of the Big Five great armies in the world.
<h3>Immigration act and Japanese Values:</h3>
Tension arose when America introduced the immigration act, where it banned all Asian immigration, later on, the whole world was in a depression in the era of nationalism in Japan, where traditional Japanese values were emphasized.
<h3>Military exerts politics:</h3>
Ultra-nationalistic military troop murdered the Japanese prime minister and militarily imposed its power in domestic and international politics. Japan signs the agreement with Nazi Germany against anti-communists. In 1938 Japan started a war with China and captured the city of Nanjing, Within four months Japanese military killed 250,000 to 300,000.
<h3>The attack on Hawaii and Americans declaration of war on Japan</h3>
In 1940 Japan joins Italy and Germany. In same year Japan bombed the Chinese city Ningbo. In 1941 they invaded Philippines, Malaysia, Hong Kong, Thai land, Guam and Wake Island, Burma and reached India (under the British rule). In the same year, the Japanese launched a surprise attack on Pearl Harbor in Hawaii, killed 2,500 and 12 ships were sunk. Then, US and partners declared war on Japan.
