[7] In December 1908 he was promoted to lieutenant and fought against the German Empire[citation needed] in World War I in Shandong, China in 1914.

[7] In 1922, upon his return to Japan, Major Yamashita served in the Imperial Headquarters and the Staff College, receiving promotion to lieutenant-colonel in August 1925.

[citation needed] After the February 26 Incident of 1936, he fell into disfavor with Emperor Hirohito due to his appeal for leniency toward rebel officers involved in the attempted coup.

He insisted that Japan should end the conflict with China and keep peaceful relations with the United States and Great Britain, but he was ignored and subsequently assigned to an unimportant post in the Kwantung Army.

[citation needed] From 1938 to 1940, he was assigned to command the IJA 4th Division which saw some action in northern China against insurgents fighting the occupying Japanese armies.

[8] Throughout his time in the military, Yamashita had consistently urged the implementation of his proposals, which included "streamlining the air arm, to mechanize the Army, to integrate control of the armed forces in a defense ministry coordinated by a chairman of Joint Chiefs of Staff, to create a paratroop corps and to employ effective propaganda".

It was his belief that victory in Malaya would be successful only if his troops could make an amphibious landing—something that was dependent on whether he would have enough air and naval support to provide a good landing site.

The plan was to conquer Malaya and Singapore as quickly as possible in order to overcome any numerical disadvantage and minimize any potential losses from a long, drawn-out battle.

[citation needed] The Malayan campaign concluded with the fall of Singapore on 15 February 1942, in which Yamashita's 30,000 front-line soldiers captured 80,000 British, Indian and Australian troops, the largest surrender of British-led personnel in history.

[citation needed] The campaign and the subsequent Japanese occupation of Singapore included war crimes committed against captive Allied personnel and civilians, such as the Alexandra Hospital and Sook Ching massacres.

'[11] Yamashita later apologized to the few survivors of the 650 bayoneted or shot at Alexandra Hospital, and allegedly some soldiers caught looting in the aftermath of the slaughter were executed.

[citation needed] In his article, Akashi argued that the main issue was that despite being an excellent tactician and leader, his personal ideals constantly placed him at odds with the General Staff and War Ministry.

[citation needed] Despite the finger of blame for the Sook Ching Massacre being pointed at Yamashita, it is now argued that he had no direct part in it, and his subordinates were the ones behind the incident.

[13] On 17 July 1942, Yamashita was reassigned from Singapore to far-away Manchukuo again, having been given a post in commanding the First Area Army, and was effectively sidelined for a major part of the Pacific War.

It is thought that Tojo, by then the Prime Minister, was responsible for his banishment, taking advantage of Yamashita's gaffe during a speech made to Singaporean civilian leaders in early 1942, when he referred to the local populace as "citizens of the Empire of Japan" (this was considered embarrassing for the Japanese government, who officially did not consider the residents of occupied territories to have the rights or privileges of Japanese citizenship).

[14] On 26 September 1944, when the war situation was critical for Japan, Yamashita was rescued from his enforced exile in China by the new Japanese government after the downfall of Hideki Tōjō and his cabinet, and he assumed the command of the Fourteenth Area Army to defend the occupied Philippines on 10 October.

[15] Because Yamashita, who also served as the governor-general and military governor of the Philippines, did not declare Manila an open city while he evacuated most of his soldiers northward, Imperial Japanese Navy (IJN) Rear Admiral Sanji Iwabuchi re-occupied Manila with 16,000 sailors, with the intent of destroying all port facilities and naval storehouses.

[16] The battle and the Japanese atrocities resulted in the deaths of more than 100,000 Filipino civilians, in what is known as the Manila massacre, during the fierce street fighting for the capital which raged between 4 February and 3 March.

Yamashita continued to employ delay tactics to maintain his army in Kiangan (part of the Ifugao Province), until 2 September 1945, the day of the formal surrender of Japan to General Douglas MacArthur.

At the time of his surrender, to Major General Robert S. Beightler,[17] Yamashita's forces had been reduced to under 50,000 by the lack of supplies and tough campaigning by elements of the combined American and Filipino soldiers including the recognized guerrillas.

It was argued that Yamashita was in full command of the Japanese Army's secret military police, the Kempeitai, which committed numerous war crimes on POWs and civilian internees and he simply nodded his head without protest when asked by his Kempeitai subordinates to execute people without due process or trials because there were too many prisoners to do proper trials.

[19][20] The principal accusation against Yamashita was that he had failed in his duty as commander of Japanese forces in the Philippines to prevent them from committing atrocities.

[21] American lawyer Harry E. Clarke Sr., a colonel in the United States Army at the time, served as the chief counsel for the defense.

[25]The legitimacy of the hasty trial was questioned at the time, including by Justice Frank Murphy, who protested various procedural issues, the inclusion of hearsay evidence, and the general lack of professional conduct by the prosecuting officers.

[28] Following the Supreme Court decision, an appeal for clemency was made to U.S. President Harry S. Truman, who declined to intervene and left the matter entirely in the hands of the military authorities.

[29] On 23 February 1946, Yamashita was hanged at Los Baños, Laguna Prison Camp, 30 miles (48 km) south of Manila.

The Arizona Republic alleges that his reply, through a translator, was thus: As I said in the Manila Supreme Court that I have done with my all capacity, so I don't ashame [sic] in front of the gods for what I have done when I have died.

On 23 December 1948, Akira Mutō, Yamashita's chief of staff in the Philippines, was executed after being found guilty of war crimes by the International Military Tribunal for the Far East.

This doctrine of command accountability has been added to the Geneva Conventions and was applied to dozens of trials in the International Criminal Tribunal for the former Yugoslavia.