Here’s another belated observation about a Sunday news show. On CNN Late Edition, Wolf Blitzer interviewed Senators Pat Roberts and Dianne Feinstein, the chair and the ranking Democrat on the Senate Intelligence Committee, and he asked them about the story of an aborted 2003 al Qaeda plot to attack New York’s subways. Both senators were circumspect, as you’d expect. But Roberts suggested something — and Feinstein appeared to back him up — that I found remarkable. Blitzer starts off (emphasis added):

Senator Roberts, the chairman, let me start with you and read to you from the new edition of Time Magazine, our sister publication, an excerpt from the book, "The One Percent Doctrine" by Ron Suskind.

In it, this paragraph: "There would be several placed in subway cars and other strategic locations and activated remotely. This was well past conception and early planning. The group was operational. They were 45 days from zero hour. Then Ali told his handlers something that left intelligence officials speechless and vexed. Al- Zawahiri had called off the attacks," referring to Ayman al-Zawahiri, the number two Al Qaida leader behind Osama bin Laden.

A report that there were cyanide gas attacks planned for the New York subway system that were inexplicably called off. What can you tell our viewers about this?

SEN. PAT ROBERTS (R), KANSAS: Well, not very much, except to say the Intelligence Committee is briefed on these kinds of threats. I would simply say that we’ve had a briefing.

It points up, once again, the value of the terrorist surveillance program, the NSA program that’s been in the news so much. We are able to detect and deter and stop such attacks. And we were very fortunate that that did not happen.

BLITZER: But can you confirm that there was such a plot in the works?

ROBERTS: I can’t either confirm or deny, but I can just simply repeat that we are briefed on these kind of threats. And, as I say again, I’m very happy we have the capability to do what we do to stop these attacks. And that goes back to the statement you’ve heard a lot that, you know, thank goodness we’ve not had an attack of that nature since 9/11. But that’s not by accident.

BLITZER: Senator Feinstein, I know you’re restricted on what you can say about these kinds of sensitive intelligence-related matters.

Two former intelligence officials have told CNN there was such a plot in the works. We have not been able to confirm that they were only 45 days off of actually launching it. But go ahead and add whatever you want.

SEN. DIANNE FEINSTEIN (D), CALIFORNIA: Well, I think the chairman said what could be said about it. I don’t think that anybody doubts that there are people that want to do us harm, that there are those that want to launch these attacks. They will if they can.

And so, you know, there’s the need for eternal vigilance. And I think Senator Roberts is correct. The terrorist surveillance program is an important tool in this area.

And there’s only one defense and that is good intelligence. And there is a very real need for us to do everything we can on the Intelligence Committee to see that the intelligence community, all 16 agencies, have really recovered from what led to the Iraq adventure, which was mistaken information, and that we get it correct.

And in fact, good intelligence has stopped what were real threats. And I think that’s important for the American people to know.

Sen. Feinstein is not exactly a shill for the Bush administration. I interpret those statements as strong hints — quite strong, within the constraints of the "we can’t confirm or deny specifics, we can only speak in generalities" paradigm — that the NSA’s international communications surveillance program played a critical role in learning about — and perhaps deterring the execution of — an attack on New York subways.

That seems pretty significant to me. I suspect that it’s as close to confirmation of a direct benefit from the NSA program as we’re likely to get — until the historians get their hands on the relevant documents about 50 years from now.