Sooden was born and raised in Zambia. His parents are Sikhs from Kashmir. His great-grandfather fought for the British Indian Army in World War I and died in Basra in 1916 during the Mesopotamian Campaign. As an inspiration for peace work, he cites his grandfather who was a career soldier in the British Indian Army and then the Indian Army. He says he was also motivated by the experiences of a friend who survived the World Trade Center attack on 11 September 2001, and the ordeal of Maher Arar, a university classmate who was subjected to extraordinary rendition and torture.