[2] With a Boxer Indemnity Scholarship, he transferred to Purdue University in the United States to complete his senior year in 1923, where he graduated in 1924.

China was in the middle of a nationalist drive to unite the divided[clarification needed] country and to protect the nation against imperialists.

[3] In 1927 Sun toured Europe and Japan to see the latest military organization and strategic thinking, then returned to China and became a corporal in the National Revolutionary Army and the Central Political Institute.

He was then given command of the National Salt Gabelle Brigade, organized by Finance Minister T. V. Soong, which he made the KMT's best trained and equipped troops.

Sun led the 113th Regiment as part of the 38th Division through difficult terrain to relieve 7,000 British forces trapped by the numerically superior Japanese in the Battle of Yenangyaung.

[5][6] Although unable to stop the Japanese from cutting the Burma Road, Sun gained the respect of General William Slim, the commander of the British 14th Army.

On May 20, 1946, Sun's troops defeated the People's Liberation Army to take a key railroad junction in the Battle of Siping, but only after a month of fighting.

[citation needed] First, Sun was reassigned as the ceremonial chief military adviser to Chiang Kai-shek in June 1954, preventing him from directly controlling any troops.

[10] On May 25, one of General Sun's subordinates, Lieutenant-Colonel Kuo Ting-liang, was arrested by Chiang Ching-kuo's associate, internal security chief Mao Jen-feng, and tortured into admitting conspiracy with a communist agent.

A nine-person committee under Vice-President Chen Cheng was set up to investigate General Sun's involvement in the alleged spy case.

[11][12] Sun, in addition to being under suspicion of collaborating with the CIA, was also accused of negligence in allowing his subordinate to participate in an alleged revolt involving Communist agents.

One source suggests that the "plot" may simply have been a plan to present a petition to Generalissimo Chiang to do away with the army system of political commissars.

Sun remained under house arrest for more than three decades: his charge was not relieved until March 20, 1988, shortly after the death of Chiang Ching-kuo.

[13] His funeral was conducted with full military honors and with the presence of the Minister of National Defense and top generals.