"Soviet preparations in the Far East, and the more general build-up of the Red Army, were well covered by Japanese intelligence, not least the development, by the end of 1935, of a 170-strong long-range Soviet bomber force able to reach Japan. In turn, the Japanese army produced plans for an invasion of the Soviet Far East and eastern Siberia. The Soviet government saw the challenge it faced in ideological and geopolitical terms. Reports in late 1935 about an Anti-Comintern Pact, which Japan, in fact, was to sign with Germany on 25 November 1936, led Soviet strategists to fear a war on two fronts, as opposed to their previous confidence that they would be able to fight on one front at a time. This fear prefigured their concern in the 1970s and 1980s about conflict with both the USA and China. In January 1936, Marshal Mikhail Tukhachevsky, the commander of the Red Army (who was to be shot on the night of 12 June 1937), pressed the Central Committee of the Communist Party on the need to confront the danger of simultaneous war with Germany and Japan. Concern about Japanese intentions towards neighbouring Mongolia led the Soviet Union to sign a pact of mutual assistance with Mongolia and to warn Japan against expanding there. Moreover, signing a non-aggression pact with China on 21 August 1937, and supplying Jiang Jieshi with plentiful arms, including 297 planes flown by Soviet pilots, and over 3,000 advisers, were steps taken by Stalin to divert Japan into a new intractable commitment in China. Full-scale war had broken out between Japan and China in July 1937, and Japan captured Beijing, Shanghai and the Chinese capital, Nanjing, that year."