[3] He became a representative of the Palestine Arab Higher Committee at the United Nations General Assembly.
He was a member of the Arab Higher Committee from 1946 and headed its treasury department, the Palestine National Fund.
[3] Tannous published a book entitled The Palestinians: A Detailed Documented Eyewitness History of Palestine Under British Mandate in 1988.
[6][10] Tannous was part of the Nakba generation who held a moderate approach and denied the use of violent ways to overcome of the problems of the Palestinians due to their forced leave of Palestine.
[2] Tannous died in Arlington, VA, on 6 August 1993 and was buried at the Protestant Evangelical Cemetery in Beirut, Lebanon.