If President Obama were to ask me why he should free Jonathan Pollard I would tell him that according to Jewish Law there is the concept of Pidyon Shvuyim which means it is a great mitzvah to free a captive, as captivity is viewed as even worse than starvation and death.
Maimonides, the Jewish philosopher wrote: “The redeeming of captives takes precedence over supporting the poor or clothing them. There is no greater mitzvah than redeeming captives for the problems of the captive include being hungry, thirsty, unclothed, and they are in danger of their lives too. Ignoring the need to redeem captives goes against these Torah laws: “Do not harden your heart or shut your hand against your needy fellow” -“Do not stand idly by while your neighbor’s blood shed.”
The Shulchan Aruch adds: “Every moment that one delays in freeing captives, in cases where it is possible to expedite their freedom, is considered to be tantamount to murder.”