During the Korean War, Zhou served as the Chief of the Political Bureau of the People's Volunteer Army, and interrogated captured POW's.
After serving in Pakistan for four years, Zhou returned to Beijing in 1955 as Section Chief of the Department of West Asian and North African Affairs.
Replacing his former superior Yao Guang, whose lack of progress the PRC government had become disenchanted with, Zhou remained in constant talks with the British delegation for 13 years until the official handover of Hong Kong in 1997.
[3] On September 26, 1984, Zhou Nan and British delegation head Sir Richard Evans initialed the important Sino-British Joint Declaration (中英联合声明) at the Great Hall of the People in Beijing.
[4] It was later formally signed by the British Prime Minister Margaret Thatcher and the Chinese Premier Zhao Ziyang again in the Great Hall of the People on 19 December 1984.
Although he wore old-fashioned glasses and drab Chinese-made suits, he spoke fluent English and was regarded as a sophisticated international diplomat.