defector:
(plural: ‘defectors‘)
Oleg Gordievsky, defector — from Russia to England in 1985
a person who leaves a political party, particular group, movement or own country, usually in order to join an opposing party, group or movement;
a person who leaves (escapes from) his country without permission and takes up shelter (even citizenship) in another country for political reasons, i.e. high level military officer, wealthy industrialist, an intellectuals go away from their own country in order to escape punishment or even death when there is some political disturbance in their own country and takes shelter and protection in another country, for instance, during Nazi regime in Germany several important people fled to (defected to) the USA, one of them was Albert Einstein;
a person who leaves from (quits) his duty without permission in military, especially a soldier on a lookout post; a deserter,
Albert Einstein, defector — from Germany to the States in 1933
Of the many defectors from Nazi Germany during WWII to the USA, Albert Einstein was one among several scientists.
During the Cold War between the USA and the USSR (Soviet Russia), there used to be several Russian defectors to America.
In the present Middle East Asian politics, there are number of defectors to the USA and the UK from countries like Iraq, Iran, Syria and Libya, who ran away from their countries for fear of their lives and their families.
