保定陸軍軍官學校
In 1929, Tang Shengzhi, a former student of Jiang at the Baoding Military Academy, turned against Chiang Kai-shek, the leader of the Kuomintang-led Nationalist government. In January 1930, Jiang was implicated and imprisoned because of his close ties to Tang Shengzhi. He was released in 1931 after the Mukden Incident broke out. In 1931, Jiang travelled to Japan on a study tour and realised that an impending war between China and Japan was inevitable. After returning to China, he formulated many defensive strategies and urged the Nationalist government to prepare for war.