The primary theme developed by Ha Jin in his story called “A Decade”, which is one of twelve short stories included on the collection named Under The Red Flag, was the war fought among China's youth and the Red Guards during China's Cultural Revolution occurred between 1966 and 1976.
In such period of time, China's youth rose together against the four 'Olds old culture, old habits, old ideas, and old customs while the Red Guards empowered by Mao terrorize them in order to purge from them all Revolutionary ideas.