Diaries and documents have come to light that support suggestions Japan’s Emperor Hirohito was more in favour of the attack on Pearl Harbour in 1941, and the subsequent invasion of the Allies’ territories across the Asia-Pacific, than is detailed by the country’s post-war history.
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.
When the talks with the US once again became bogged down, Hirohito became more cautious about an attack.
“The documents are important because they can give us a better understanding of the thinking of Japanese leaders during the Sino-Japanese War and in the weeks immediately before the start of the Pacific War,” said Takahisa Furukawa, a professor of modern Japanese history at Nihon University.
Furukawa said the papers supported other documents, including Kido’s diaries, indicating that the emperor fluctuated from backing a war to wanting to safeguard peace.
“After Japan’s proposal for a US-Japan summit was rejected in early October [1941], it is thought that the emperor gradually leaned towards the idea that while he did not want to go to war, it was increasingly unavoidable,” Furukawa said. “Other documents have made a similar point, but these diaries explain the emperor’s feelings immediately before [the assault on Pearl Harbour].”
That attack was designed to cause extensive damage to the US Pacific fleet, in particular its aircraft carriers, giving Japan the time it needed to capture Hong Kong, invade the Malay Peninsula, conquer Singapore and launch offensives against India, Australian forces in Borneo and islands scattered across the Pacific.
But Imperial Japan’s plans faltered from the outset when the US aircraft carriers were not in port and escaped unscathed.
“Since the end of the war, the emperor has been distanced from the implementation and execution of the imperial adventures of the early decades of the last century,” said Stephen Nagy, an associate professor of international relations at Tokyo’s International Christian University. “That was the result of an implicit bargain that the Allied occupation forces would not find the emperor responsible for the war.”
Historians have said the US and its Western Allies were motivated to distance Hirohito from blame as they feared prosecuting the nation’s revered figurehead would antagonise the Japanese people and potentially trigger resistance to the American occupation of Japan.
Another consideration was the need to have a pro-US nation in the Far East to support Washington’s strategic ambitions as the Iron Curtain was descending in Europe and the US faced an increasingly hostile Soviet Union.
But not all conservative academics agree that Hyukutake’s documents are of historical importance. Yoichi Shimada, a professor of international relations at Fukui Prefectural University, said he was sceptical about their significance.
“These diaries prove nothing and are only the reported thoughts of the emperor,” he said, adding that the conventional wisdom that the emperor was strongly opposed to expanding the war beyond China was “far more likely”.
“The emperor was very much striving for rapprochement with the US and Britain,” Shimada said. “He is known to have been very pro-British and to have close links with the British royal family. I do not believe that he was intimate with the details of the operations that started the Pacific War.”
Hyukutake’s documents have been donated to the University of Tokyo’s Centre for Modern Japanese Legal and Political Documents and were made available to historians before being put on public display earlier this month.