How did the attack on Pearl Harbour in 1941 turn the tide against the Japanese during World War 2? Japan began their deadly attack on the U.S pacific fleet moored at pearl harbour on the pacific island of Oahu, at 07:55, December 7 1941. This attack turned the tide on Japan because war had not yet been declared between the two countries and up until that point, America enters the war after years of neutrality. “Although quick in execution, the attacks years.’’[Source B] Japan relied on America to supply many of the natural and industrial resources, but taken aback and alarmed by Japan’s aggression towards them, America allowed the commercial treaty they had with japan dating back thirty one years, to expire in 1940.[source B] Japan was looking