MICHELE NORRIS, host:

The Pentagon changed commanders in Afghanistan when Secretary of Defense Robert Gates announced yesterday the resignation of the top general there, General David McKiernan. He had held the job for only 11 months and is being replaced by Lieutenant General Stanley McChrystal. Gates cited the need for a change of military thinking and fresh eyes. And he pointed to McChrystal's background in counterinsurgency.

Here to talk about the new appointment and what it means for U.S. strategy in Afghanistan is Andrew Exum, a fellow with the Center for a New American Security. He served under Lieutenant General McChrystal, leading a special operations force in Iraq and Afghanistan. Welcome to the program.

Mr. ANDREW EXUM (Fellow, Center for a New American Security): Thank you very much. Good to be here.

NORRIS: So if Gates is calling for fresh thinking and if the White House is looking for a new path forward, what do they want him to do differently?

Mr. EXUM: Well there are a couple of things. First off, when you hear people talk about Afghanistan, you hear people talk not just about new resources but also the need to partner those resources with an effective strategy and the leaders to carry out that strategy. With the publication of the White House white paper on Afghanistan and Pakistan, you have the evolution of a new strategy. But the unfortunate thing is, is that you have to find very specific people to carry out that strategy.

NORRIS: So when you talk about carrying out strategy, help me understand why McChrystal would be better able to do that.

Mr. EXUM: I believe there is a sense that - we talk a lot in the Army about understanding the intent of your higher commander. And there is the sense I believe in not only the White House but also of the Department of Defense and then United States Central Command that General McChrystal has kind of that mind meld with General Petraeus, that they see the problem similarly.

So it's one thing when General McKiernan talks about population-centric counterinsurgency. He may be thinking about something that looks very different than what General Petraeus thinks when he thinks population-centric counterinsurgency.

NORRIS: Now General McChrystal will still have to go through a confirmation. What are some of the tough questions that he might face?

Mr. EXUM: I think that General McChrystal has two potential roadblocks in front of his confirmation. The first is the aftermath and the way that the death of Specialist Pat Tillman was handled in 2004.

NORRIS: The former Arizona Cardinal.

Mr. EXUM: Absolutely. He was a member of the second battalion of the U.S. Army's Ranger regiment at the time when he was killed. And General McChrystal was involved in the - in the fallout. Now General McChrystal sent a famous Email back to his superiors in the immediate aftermath saying that, hey, look, you know, before you go further with this, the lionization of Specialist Tillman, there are a few things you need to know. So he covered himself to a degree there.

In addition, in late May, we should expect the final release of the detainee pictures that the ACLU has requested and has - been granted the release of, some 20,000 pictures. General McChrystal headed a task force that was accused of abusing detainees. There were several members of that task force who were in fact incarcerated. So I think that the greater issues of detainee abuse could come to bite him in a confirmation hearing and it will be interesting to see how that is handled.

I do not think that as savvy a political actor as Secretary Gates would have let this nomination go forward if he thought that either of these was going to be serious problems. But we will see how the climate is on Capitol Hill when his confirmation hearing takes place.

NORRIS: How do you think the news of his appointment will be met on the ground there?

Mr. EXUM: I think that those who have worked underneath General McChrystal will be quite heartened. I think that it shows a certain degree of ruthlessness to remove a commander, to really fire a commander quite publicly in a humiliating manner. It shows that we are serious about a change in strategy in Afghanistan. On the other hand I think that within the United States Army officer corps this will be met with a degree of sadness. General McKiernan is not seen as an incompetent officer. He is probably just the officer that is not right for this particular moment. And that the stakes were simply too high to not replace him with the officer that the president, the Secretary of Defense and General Petraeus feel is best suited for the environment.

NORRIS: Andrew Exum, thank you very much for coming here to talk to us.

Mr. EXUM: Sure thing.

NORRIS: Andrew Exum is a fellow with the Center for a New American Security. Transcript provided by NPR, Copyright NPR.