Barrett was part of the American military experience in China, and played a critical role in the first official contact between the Chinese Communist Party and the United States government.

He taught high school English for the next two years, but when the United States entered the First World War, he reenlisted, earning a commission as a second lieutenant.

From that position, he watched the Kuomintang's encirclement campaigns against the Chinese Communists, who, in Barrett's opinion, were irresponsibly and wrongly designated as bandits by the KMT.

The most notable event that Barrett personally witnessed was the Marco Polo Bridge Incident in 1937, which began the Second Sino-Japanese War.

Another problem was the habit of Nationalist officials to bypass Barrett and communicate directly with the American military personnel.

His wishes were granted and he found himself assigned to assist in the American creation of a Chinese field army at Guilin in the Guangxi Province in southern China.

On March 24, Barrett received an order to proceed to Chongqing for temporary duty, unaware of the plans for the observer group to Yan'an.

At the time, Generalissimo Chiang Kai-shek had not yet provided his consent to the mission and Barrett waited a month in Chongqing before being ordered back to Guilin.

Paul Domke, 1st Lt. Henry Wittlesey, Staff Sgt Anton Remeneh, US Embassy 2nd Secretary John S. Service and political attaché Raymond Ludden arrived in Yan'an on July 22, 1944.

While serving as a courier and representative for Wedemeyer's chief of staff, General Robert B. McClure, Barrett was sent on two missions to Yan'an to speak with Communist leadership.

Hurley stopped a promotion in motion to make Barrett a brigadier general and had him removed to a small corner of the China theater for the rest of the war.

One year later, he was falsely implicated as the leader of a conspiracy to have Antonio Riva and Ruichi Yamaguchi assassinate Mao Zedong with a mortar strike on Tiananmen Square during National Day celebrations.

Although Riva and Yamaguchi were executed and several other expatriates were imprisoned, in 1971 Premier Zhou Enlai explained that claiming his involvement had been a mistake, apologized to Barrett, and invited him to visit the country again.

In 2013, the story of the Dixie Mission served as the historical basis for a new World War II novel called Two Sons of China, by Andrew Lam.