In 1964, Trần Hữu Chất enlisted in the army once again, serving in what was known as Front B in Quảng Nam Province. At this front, his principal mission was to integrate with the village population and local troops in order to depict with his drawings the reality of Vietnam during the Second Indochina War. Among his many anecdotes, Chất explained how he was captured by Việt Cộng guerrillas in the village of Đặc Xảy, where he was almost shot for being mistaken as a collaborator with American troops.
Chất was present in Da Nang during the Tết Offensive that began on 31 January 1968. Just over 100 kilometres away from Huế in Da Nang, Chất was not far from the Battle of Huế, a battle that has become notorious throughout history.
During the war, Chất worked daily with ethnic minority groups. These people inspired many of his drawings, which demonstrated the local people’s support in the resistance movement. Chất is particularly well known for his depictions of the Bà Nà tribe. During this time, he also published a collection of poetry under his pseudonym, Hồng Chinh Hiền.

Chất depicted the Bà Nà people with accuracy. The Bà Nà lived primarily in the Central Highland provinces of Gia Lai and Kon Tum, as well as the coastal provinces of Bình Định and Phú Yên. While in Quảng Nam Province, Chất made many excursions to their villages, which were nestled in the mountain forests. Depicting only men in these paintings (figs. 1 and 2), Chất shows Bà Nà men wearing their traditional loincloth together with colourfully embroidered shawls.
