You seem to have a basic misunderstanding of the penalties handed out to Americans who steal classified information and give it to someone else. It has nothing to do with who receives the information and more to do with the importance of the information itself. Pollard received a life sentence because of what information was compromised. According to a classified memorandum written for the trial judge by then-Secretary of Defense Caspar Weinberger, Pollards actions amounted to treason. It is difficult for me to conceive of a greater harm to national security, Weinberger wrote.
We have had others who have spied on behalf of Israel, e.g., Larry Franklin, who were not sentenced to life. And there have been other spies like Aldrich Ames and John Walker who received life sentences. To suggest that Pollard was unfairly singled out in terms of punishment is nonsense. Why do you believe that to be the case?
I'd suggest you read the espionage statutes and the case law that has arisen from them. I would respectfully suggest that both who recieves the information and the importance of the information itself should be and have been important factors in a damage estimate in such cases.
As for Weinberger's memorandum in the Pollard case, perhaps the time will soon come when it will be declassified so we will be better able to evaluate it in terms of accuracy.
Meanwhile, I do have a suspicion that the late, black Carter-appointed judge did have an anti-Israel bias - considering his skin color (blacks are statistically far more likely to harbor antisemitic and anti-Israel attitudes than whites) and the biases of the man who appointed him to the federal bench.