New insights into intelligence role in start of Pacific war

MinoharaPULLMAN, Wash. – Recently uncovered documents about prewar Japanese intelligence that offer new insights into World War II will be discussed in a free public presentation at Washington State University Pullman. Tosh Minohara, professor in the Graduate School of Law at Kobe University, Japan, will present “Reconsidering the Road to Pearl Harbor: The Role of Intelligence in Decision Making,” noon-1:30 p.m. Wednesday, Sept. 25, in Bryan Hall 324. 

His approach will be two-fold: first, to briefly overview the obscure history of the Japanese Black Chamber, a code breaking operation; and second, to examine the intelligence dimension of policy formulation in Tokyo. This will include the impact of signals intelligence on decision making, most notably at the critical juncture of November 1941 during U.S.-Japan negotiations.

Minohara said he will offer a more rational explanation behind the hitherto unexplained Japanese foreign minister Togo’s hensetsu (about-face) from earlier reluctance to go to war with the U.S.

Newly revealed information from the National Archives II, the National Security Agency, the Japanese Diplomatic Records Office of the Ministry of Foreign Affairs in Tokyo, and the British National Archives (formerly PRO) provides background for the presentation sponsored by the WSU Department of History (, the George and Bernadine Converse Historical Endowment and the WSU Asia Program (

Minohara is a specialist of U.S.-Japan relations with academic interest in politics, diplomacy and intelligence. He earned a bachelor of arts degree from the University of California Davis and a Ph.D. in political science from the Graduate School of Law, Kobe University.

His many publications include “The Japanese Exclusion Act and U.S.-Japan Relations: The Truth behind the ‘Grave Consequences’ of the ‘Hanihara Note’” (Tokyo: Iwanami Shoten, 2002), which won the Shimizu Hiroshi Book Award from the Japanese Association for American Studies; “The Anti-Japanese Movement in California and U.S.-Japan Relations: The Friction between Japan and the U.S. over the Immigration Problem in 1906-1921” (Tokyo: Yuhikaku, 2006); and, as co-editor and contributor,  “Tumultuous Decade, Empire, Society and Diplomacy in 1930s Japan” (University of Toronto Press, 2013).

Noriko Kawamura, WSU associate professor of history, 509-335-5139,