Some of Barack Obama's advisers have talked publicly of keeping on Robert Gates as secretary of defense in a Democratic administration. Gates, who has been widely praised for his pragmatic stewardship of the Pentagon, says firmly he wants to go home to Washington state. But he agreed to talk to NEWSWEEK's John Barry about the national-security challenges he sees ahead. Excerpts:

Barry: So, what awaits the next president?
Gates: I entered the CIA 42 years ago, and I think that the world is as complex and in a real way more dangerous than at any time since then.

More dangerous than the cold war?
In the cold war, you had the cosmic risk of nuclear war with the Soviet Union. But the truth is that, other than the Cuban missile crisis and maybe one or two other occasions, that threat was really theoretical. The missiles were real, but both powers had learned to deal with each other. We had rules of the road even between the KGB and CIA. And so there was a fair amount of predictability; we kind of observed red lines.

And now there are no red lines?
Look around. Iran. North Korea. A Russia that people have a hard time figuring out what to make of. The Chinese are not so much a security challenge, but they clearly have some very significant military modernization programs underway that are worrisome. North Korea: what's going to happen now? The entirety of Central Asia, where you have pressures on them from Russia to toe the line, and their wanting to maintain some sense of independence—but how much? Again, nobody knows where that line is … The problems that Pakistan faces. So you've got all of these. You've got the whole Israeli-Palestinian-Syrian challenge. In our own hemisphere, Venezuela. And then, of course, there is Al Qaeda and a variety of violent extremists that are still very much out there. That's a pretty long list of challenges that the new guys need to be prepared to deal with from day one.

But a more dangerous world?
The reason I said it was a more dangerous world ... is that the consequences of conflict, or an attack, are not nearly as cataclysmic as had there been a conflict with the Soviet Union. But the risks of one are far greater.

And, of course, the next president will inherit two wars …
We are engaged in two very difficult wars. One of them, [Iraq], seems on the way toward a positive outcome—particularly given where we were. But the other is going to be a slog, and it's more complicated because we have many more nations involved—not just on the military side, on the civilian side, too. So … managing that is much more difficult in Afghanistan.

You took over from Donald Rumsfeld …
One of the things that annoys me is that everyone is always trying to contrast everything I do with everything Secretary Rumsfeld did. But the transformation that he started has totally changed the American military, and, I believe, for the better.