Military diaries indicate Japan’s Emperor Hirohito backed Pearl Harbour attack

The family of the late Admiral Saburo Hyukutake have handed over to academics more than 20 volumes of diaries and notepads covering the eight years from 1936 that he spent as grand chamberlain to the emperor, national broadcaster NHK has reported.

Historians say the documents show Hirohito wavering between hoping for peace with the United States, Great Britain and the Netherlands, followed by a sudden swing to supporting a war against nations that his military leaders insisted were attempting to strangle Japan with sanctions and opposing its ongoing occupation of China.

His backing of the conflict runs counter to the widely held understanding in Japan today that the emperor – who ruled from 1926 until his death in 1989 – was consistently reluctant about becoming embroiled in a disastrous war, and was only browbeaten by his military leaders into eventually giving his approval.

The diaries make it clear that he frequently met senior officials and the military leaders who made up the cabinet in the late 1930s and in the months leading up to the attack on the US fleet at Pearl Harbour, in Hawaii, on December 7, 1941.

Just 18 days before the attack, Hyukutake had written that Koichi Kido, Lord Keeper of the Privy Seal and the emperor’s closest adviser throughout World War II, stated that Hirohito was showing “determination” to go to war.

According to the diaries, Kido, who claimed after the war to have known nothing in advance about the military’s plans to attack Pearl Harbour, had informed the emperor that then US president Franklin Roosevelt was leaning towards concluding negotiations on the easing of the fuel embargo that was crippling Japan.

They also show that Kido was strongly in favour of avoiding war and did not hesitate to speak his mind, even in front of dissenting military officers in the government.