The issue here is the severity of the sentence. Compared to sentences assigned to other crimes a life sentence appears unreasonable. I think it is clear that by assigning such a severe sentence it was intended that he be made into an example. That is not justice. 30 years is enough.
2 Turkish security personnel killed, 24 wounded by Kurdish suicide bomb in eastern Turkey (Reuters)
from the article: Israeli Knesset discusses jailed spy Jonathan Pollard