‘Forewarned Is Forearmed’: Intelligence, Japan's Siberian Intervention, and the Washington Conference

Abstract

This article details the intelligence-gathering role of US railroad experts stationed in Siberia and Manchuria from 1917 to 1922. Beginning in April 1920, US railway officials began receiving intercepted correspondence between Japanese officials, passed to them from Japan's military headquarters in Harbin via a former Czechoslovak soldier. The intelligence shows that US officials were aware of highly detailed planning by Japanese expansionists. Whether or not US officials were completely cognisant of the intelligence's significance, these sources provide insight into why US diplomacy helped provide leverage to the moderates within Japan's government. In particular, the intercepted correspondence allows for a reinterpretation of Japanese Foreign Minister Uchida Yasuya's role during the Siberian expedition. This paper provides evidence that Uchida was not a moderate ally as scholars have traditionally claimed, but a key facilitator of Japan's military expansionists. It argues that the success of the Washington Conference, combined with the military's repeated failures to produce a victory in the Russian Far East, pressured Uchida into withdrawing his support for the expansionist programme. In addition to demonstrating the impact of the Washington Conference and the Siberian intervention on US–Japanese relations, this article helps explain Uchida's later re-emergence in the 1930s as a militarist sympathiser.