Bill Keller, executive editor of the New York Times, has written an open letter to critics assailing his paper for publishing a story that the U.S. government has been scouring the records of "terrorism suspects."

Some excerpts:

Since September 11, 2001, our government has launched broad and secret anti-terror monitoring programs without seeking authorizing legislation and without fully briefing the Congress. Most Americans seem to support extraordinary measures in defense against this extraordinary threat, but some officials who have been involved in these programs have spoken to the Times about their discomfort over the legality of the government's actions and over the adequacy of oversight. We believe The Times and others in the press have served the public interest by accurately reporting on these programs so that the public can have an informed view of them.

Our decision to publish the story of the Administration's penetration of the international banking system followed weeks of discussion between Administration officials and The Times, not only the reporters who wrote the story but senior editors, including me. We listened patiently and attentively. We discussed the matter extensively within the paper. We spoke to others — national security experts not serving in the Administration — for their counsel. It's worth mentioning that the reporters and editors responsible for this story live in two places — New York and the Washington area — that are tragically established targets for terrorist violence. The question of preventing terror is not abstract to us.

The Administration case for holding the story had two parts, roughly speaking: first that the program is good — that it is legal, that there are safeguards against abuse of privacy, and that it has been valuable in deterring and prosecuting terrorists. And, second, that exposing this program would put its usefulness at risk.

It's not our job to pass judgment on whether this program is legal or effective, but the story cites strong arguments from proponents that this is the case. While some experts familiar with the program have doubts about its legality, which has never been tested in the courts, and while some bank officials worry that a temporary program has taken on an air of permanence, we cited considerable evidence that the program helps catch and prosecute financers of terror, and we have not identified any serious abuses of privacy so far. A reasonable person, informed about this program, might well decide to applaud it. That said, we hesitate to preempt the role of legislators and courts, and ultimately the electorate, which cannot consider a program if they don't know about it.

We weighed most heavily the Administration's concern that describing this program would endanger it. The central argument we heard from officials at senior levels was that international bankers would stop cooperating, would resist, if this program saw the light of day. We don't know what the banking consortium will do, but we found this argument puzzling. First, the bankers provide this information under the authority of a subpoena, which imposes a legal obligation. Second, if, as the Administration says, the program is legal, highly effective, and well protected against invasion of privacy, the bankers should have little trouble defending it. The Bush Administration and America itself may be unpopular in Europe these days, but policing the byways of international terror seems to have pretty strong support everywhere. And while it is too early to tell, the initial signs are that our article is not generating a banker backlash against the program. ...

A secondary argument against publishing the banking story was that publication would lead terrorists to change tactics. But that argument was made in a half-hearted way. It has been widely reported — indeed, trumpeted by the Treasury Department — that the U.S. makes every effort to track international financing of terror. Terror financiers know this, which is why they have already moved as much as they can to cruder methods. But they also continue to use the international banking system, because it is immeasurably more efficient than toting suitcases of cash.

I can appreciate that other conscientious people could have gone through the process I've outlined above and come to a different conclusion. But nobody should think that we made this decision casually, with any animus toward the current Administration, or without fully weighing the issues.