(i) Japan's stand had been neutral in the initial stages of Second World War.
(ii) America was forced into the war after its naval base at Pearl Harbour was attacked by Japan on 7th December 1941. First America declared war on Japan followed by France and England.
(iii) This attack caused huge loss to America, forcing it to enter the war.
(iv) The American air-force destroyed Hiroshima and Nagasaki, the two prime cities in Japan in 1945.