It was not a public letter, it was an op-ed and it is being misreported. Here is a clarification:

The op-ed, “Refusing to Remain Silent in the Face of Evil” (Jerusalem Post, November 25, 2009) by Jonathan and Esther Pollard, was written in the interests of protecting the safety and security of the citizens of Israel.

There are no names used in the op-ed, because it is about principle. It is not personal. Its goal is to sound the alarm against reckless endangerment of the people of Israel via the infusion of massive numbers of murderers and terrorists into the civilian population of neighboring areas of Gaza and the PA.

It exposes the hypocrisy of the Government of Israel in “negotiating” a massive release of murderers and terrorists in exchange for a single captive, on the claim that this lopsided “swap” is based on the principle of never abandoning one who served the State.

The writers use a literary device, an anonymous comparison of two cases, to demonstrate that if principle were truly the reason for the Government’s insistence on making such a monstrous deal, then the same principle would rule in every case for every captive, not just for one. Because that is not the case, it is obvious that principle has nothing to do with formulating this deadly deal.

The bottom line for the Pollards is that political expedience is driving the Government’s plan to engineer the wholesale release of murderers and terrorists, not ideological concern for a captive. The Pollards warn that everyone must speak out against this evil; wanton endangerment of all citizens of Israel must not be permitted.

Read the Op-Ed here
http://www.jonathanpollard.org/2009/112509b.htm