In 1925, during his visit to Paris, Vasiliev was persuaded by Michael Rostovtzeff to emigrate to the West. It was Rostovtzeff who ensured a position at the University of Wisconsin–Madison for him.[1] Several decades later, Vasiliev moved to work in Dumbarton Oaks. Towards the end of his life, he was elected President of the Nikodim Kondakov Institute in Prague and of the Association Internationale des Études Byzantines.