TAPPER: A couple weeks ago I asked you if you had any idea how many al-Qaida members there were in Afghanistan. It had been under a hundred a couple years ago when - then-CIA Director Panetta said. Do you have - do you have an updated number?

CARNEY: I don't. I mean, I - that's probably an intelligence assessment that, if I did have it, I might not be able to share with you. But what I think was true then remains true now, which is that the region between Afghanistan and Pakistan has been a focal point of our efforts and that the goal of the Afghanistan strategy has been to both go after and remove from the battlefield leaders of al-Qaida, but also to create a situation in Afghanistan that makes it inhospitable to the hosting of al-Qaida in the future and that - that effort continues.

TAPPER: Well, OK, here's the larger question. Even though the tens of thousands of U.S. troops who are there are brave and heroic and doing what they're asked to do, do you think that the presence of U.S. troops in Afghanistan right now is actually making it more stable and less hospitable for al-Qaida, or is it doing the exact opposite?

CARNEY: I don't think there's any doubt that we have had success in the implementation of this strategy, in making life a lot harder for al-Qaida. And that has been a direct result of the president's approach in Afghanistan and Pakistan. I really don't think anybody could doubt that.

There is no question that this is hard, that the situation in Afghanistan has been and remains difficult.

And the challenges that our men and women face are significant. But it is important to remember that it is all done in the name of and with a focus on the number-one priority, which is to enhance American national security interests by disrupting, dismantling and ultimately defeating al-Qaida.

And the stabilization of Afghanistan, of its government and the building up of its security forces is done in service of that goal. And that's why the mission is so important. It is not the case - and this was debated at the time - that our policy is or should be about trying to create a Jeffersonian ideal in Afghanistan. That's not going to happen. And I know that's not what you're saying, but I'm just - I'm making this point in the context of why the focus of the mission is so important.

TAPPER: One national security expert said to me "We've reached our sell-by date there."

CARNEY: We've been there a long time. And the president has made clear that his policy is designed to allow us to draw U.S. forces down as we accomplish our goals there. And it is a very specific plan. It has a timetable attached to it, which some take issue with, although you have to wonder why, because he understands the impact that more than a decade of war has had on our armed forces and on the families of those who have sent men and women to Iraq and Afghanistan, on our economy.

And that is why it was so important to him when he was developing, in the deep dive that you remember, an Afghanistan strategy that we get it right, that we have the right priorities and the right focus, and a process in place by which to achieve our goals and draw down forces. And that is the president's plan.

TAPPER: Right, but at this point, no concern within the White House that we - that the presence of U.S. troops, even though most of them - almost all of them are doing what they're asked to do, is not doing more harm than good right now?

CARNEY: I'm confident that we believe that our presence there is having the desired effect in the implementation and achievement of our objectives, the implementation of the plan and the achievement of the objectives. There are obviously difficult challenges that we face in Afghanistan. And incidents like this do not make it any easier, no question.

-Jake Tapper