In the spring of 1936 he was appointed Vice Minister of Army Department, taking part in making plans to invade north China. He proposed to set up a military camp in Fengtai -- close to the Beijing-Tianjin Railway -- instead of Tongzhou as originally planned. And it was the army stationed in Fengtai that provoked the Lugouqiao Incident on July 7, 1937. Hence Japan launched a full-scale aggression war on China.
On July 27 Umezu prevailed over dissenting views and got his attack plan adopted. The cabinet agreed to send three divisions of some 210,000 to north China.
Owing to Chinese forces" resistance, Japan didn"t achieve its initial goal of conquering China within three months. In May 1938 Umezu was appointed General Officer commanding the 1st Army, and led his troops to invade Shanxi Province, carrying out the brutal policy of "burn all, kill all, and loot all." The Chinese forces dealt the intruders severe blows, and by September 1939 the 1st Army suffered casualties of about 21,000.
As the Nomonhan Incident inflicted heavy losses upon the Kwantung Army, the General Headquarters appointed Umezu the army"s new Commander-in-Chief in September 1939, asking him to reconstruct it, make war preparations against the Soviet Union, and speed up plundering the rich resources of northeast China.
Giving secret orders to establish 4 branches of Unit 731
Umezu was promoted senior general in 1940. Until 1944 he provided the Pacific and Chinese battlegrounds with large numbers of picked troops. In December 1940 he also signed the confidential order to establish four branches of Unit 731.
After Japan lost the Pacific War, Kuniaki Koiso replaced resigning Hideki Tojo to form a new cabinet. Umezu was appointed Chief of the General Staff. In August 1944 he mapped out a battle plan for the Japanese army and navy, advocating that the military should fight on, forcing the Allies to sustain heavy losses in a ground invasion of Japan, and that only by this way could Japan negotiate for better peace terms.
However, at that time, under a two-pronged attack by the US and the Soviet Union, Japan was unable to recover its vitality after suffering a series of military setbacks on the battlefields in the Pacific, China and other Asian countries. On July 26, 1945, the US, the UK and China jointly published the Potsdam Proclamation, requesting Japan to surrender. On August 6 the US air force dropped the first atomic bomb on Hiroshima. On August 9 the Soviet Union declared war on Japan. The second atomic bomb hit Nagasaki On August 11.
Although the fate of defeat was as good as sealed, along with War Minister Korechika Anami and Chief of Staff of the Navy Soemu Toyoda, Umezu asked to put up a desperate struggle, which was rejected by the Emperor. On September 2, the Emperor ordered Umezu and Foreign Minister Mamoru Shigemitsu to sign the Instrument of Surrender on behalf of the Japanese Imperial General Headquarters aboard the USS Missouri.
The International Military Tribunal for the Far East issued the order in April 1946 to arrest both Umezu and Shigemitsu. In November 1948 Umezu as a Class-A war criminal was sentenced to life imprisonment. He died of cancer on January 8, 1949 at Sugamo Prison.