Many, including Barack Obama, have dismissed the notion that Mir Hossein Mousavi, the leader of the opposition in Iran, would make any difference to the policy of Iran since Mousavi, among other things, is considered the father of the Iranian nuclear program, and is steeped in the ideology of the Iranian revolution. I don’t have enough specific knowledge of Mousavi to make that judgment, but people do change as a result of changed circumstances.
There was another father of a nuclear program who became a dissident against a repressive regime. His name was Andrei Sakharov, considered one of the fathers of the Soviet nuclear program, and a winner of the Soviet Hero of Socialist Labor in the 1950s. By the 1960s, Sakharov was a campaigner for the nuclear test ban treaty and human rights in the Soviet Union, and in 1975 was awarded the Nobel Peace Prize.
Different career paths, for sure. One a politician, one a scientist. But people do change, sometimes because they want change, sometimes because times change. Don’t discount how the change of circumstances may change Mousavi.