SOLEDAD O'BRIEN: We begin with a new threat in Afghanistan. Over the weekend, more than 50 Taliban fighters were killed or wounded in a raid by NATO-led troops. But that is barely a dent. Violence in Afghanistan is surging. More than 350 people died this year from insurgent attacks. It is the deadliest year since the war began. And now it has become clear that the region has become a magnet for foreign fighters who are even more extreme than the Taliban. And they brought deadlier tactics to the war and are changing the face of the enemy. Joining us this evening, CNN terrorism analyst Peter Bergen. Huge, huge influx reported in these foreign militants who are fighting alongside the Taliban. Why such an increase? Why now?

PETER BERGEN, CNN TERRORISM ANALYST: Well, Soledad, as I'm sure you're aware, the situation in Afghanistan over the last year or so has got progressively worse. IED attacks doubled in the last year. Suicide attacks quintupled, up to 139. They're already up 69 percent this year. Attacks on international forces tripled. And part of this is because of al Qaeda's influence on the Taliban. The tactics that worked, unfortunately, so well in Iraq have been imported into Afghanistan, the suicide attacks, the IED attacks. And, at the same time, there's been people going from Afghanistan to the -- to Iraq to actually learn on the job there. And some of these people are coming back. "The New York Times" reports today that there are more foreign fighters in Afghanistan, according to both U.S. officials and Afghan officials. And that's a problem, because, of course, the foreign fighters are even more radical than some of the Taliban, Soledad.

O'BRIEN: And the number they gave are 5,000 people killed. Reports say that these fighters, Peter, are coming from Pakistan, Chechnya, even Turkey and China, and that they hope to further radicalize, as you point out, some of the more moderate figures within the Taliban. What kind of long-term impact do you think this sort of influx could have?

BERGEN: Well, I think, unfortunately, it could make the already-violent situation in Afghanistan quite a lot worse.

For the complete transcript, please follow this link. Peter Bergen is a Schwartz Senior Fellow at New America Foundation.