I think there would a certain condition to his parole not to leave the country, if not he would need permission.
Just think about parole itself for a second. Just to leave the state in which the crime a person has been convicted of you would need to apply for an interstate compact, that's just to travel to another state. Imagine all the technicality with leaving the country. People on parole need permission to do everything. If Pollard is granted permission to be allowed to leave, which I doubt, they wont allow him to travel to Israel.