Jonathan Pollard (born 1954) was convicted of spying for Israel against the United States of America in 1986. He had been a U.S. Navy intelligence analyst. After being found guilty of spying, He received a life sentence without parole. The information passed by Pollard to Israel was of such importance that the U.S. Government has never allowed any details of it to be publicly revealed. The Israeli goverment denied for many years that Pollard worked for it but in 1998 the Israelis finally admitted that he had spied on their behalf.
Israeli Prime Minister Benyamin Netanyahu lobbied President Bill Clinton for Pollard's release, Clinton was willing to release Pollard, but this was strongly opposed by members of the U.S. military and intelligence communities. As of today, Pollard remains in a U.S. prison.