Quick questions on The Japanese invasion of Manchuria 1931: HSC Modern History National Study China

Manchuria (the three north-eastern provinces of Liaoning, Jilin, and Heilongjiang) covered around 1.3 million square kilometres with around 30 million people. Japan held the Kwantung Leased Territory (Liaodong peninsula) and the South Manchurian Railway zone since the Russo-Japanese War of 1904-1905. The Kwantung Army (a Japanese garrison of around 10,000) guarded the railway.

On 18 September 1931 Japanese officers of the Kwantung Army (Colonels Itagaki Seishiro and Ishiwara Kanji) detonated a small charge on the South Manchurian Railway just north of Mukden (Shenyang). The explosion did not even derail a train, but the Kwantung Army used the pretext to attack the Chinese garrison and seize Mukden.

Zhang Xueliang's forces (around 250,000) outnumbered the Kwantung Army many times over but did not resist; Chiang ordered non-resistance, gambling that internationalisation would save Manchuria. By early 1932 the Kwantung Army had taken Mukden, Changchun, Jilin, Qiqihar, and Harbin. The conquest was effectively complete by February 1932.

The puppet state of Manchukuo ("Manchu State") was proclaimed on 1 March 1932. Henry Puyi, the last Qing Emperor, was installed as Chief Executive; he was elevated to Emperor of Manchukuo (in the Kangde reign era) on 1 March 1934. The real authority was the Kwantung Army's commander, who doubled as Japanese ambassador.

Chiang's strategic doctrine (jiao gong, kang ri: "suppress the Communists, then resist Japan") rested on three assumptions: China was militarily too weak to fight Japan; international intervention would eventually constrain Tokyo; the CCP threat had to be eliminated to permit unified resistance.