Why would Israel be trying to get his release? Though Pollard acted as a mercenary, he DID pass info to Israel. If they didn’t, they’d have no spies in enemy countries. Do Palis spy for Israel for the love of Israel? No! Either the Israelis have something over them or, it is for money! If they didn’t fight for the release of their spies, they would have very few foreign spies.
Israel didn’t make the effort they’d have made for an Israeli agent, since he was just a paid source. Israel goes to great lengths to recover their agents and military, witness the disproportionate prisoner releases occasionally engaged in for corpses. Israel also has a designation, “ Prisoner of Zion”, which requires maximum effort for those imprisoned for advocacy of Zionism. People like Natan Sharansky, Yosef Mendelevitch from Russia would be examples. It’s also bestowed posthumously. Pollard requested this designation, was denied, went to court and was denied by the Israeli Supreme Court since the US doesn’t imprison Jews for being Jews, in his case they imprisoned a Jew for committing a crime, espionage. Which they noted has nothing to do with Zionism and would be a crime in the US as well.