STEPHANOPOULOS: Let me move on to the issue of Iran. You said that Iran is on a path to building nuclear weapons. But the 2007 National Intelligence Estimate concluded with a high degree of confidence that Iran had halted its nuclear weapons programs. So do you believe that intelligence estimate is outdated? Is it no longer accurate?
MULLEN: Well, I believe then and I still believe that Iran's strategic objective is to achieve nuclear weapons, and that that path continues. Their leadership is committed to it. They conducted a missile test this last week that was successful, which continues to improve their missile delivery system and capability. Their intent seems very clear to me, and I'm one who believes if they achieve that objective, that it is incredibly destabilizing for the region. And I think eventually for the world.
STEPHANOPOULOS: You said it's their intent. But do you believe they've restarted their actual nuclear weapons program?
MULLEN: I haven't seen -- or I wouldn't speak to any details about what they are doing with respect to that. Although, I remain concerned that while intelligence estimates focus on what we know, I'm concerned about what Iran might be doing that we don't know.
STEPHANOPOULOS: Let me also press the question of their strategic intent. "Newsweek" has a cover story out. Let me show you. It says that everything you think you know about Iran is wrong. And one of the points that Fareed Zakaria makes in "Newsweek" is he points out on several occasions over the last several years, Iran's leaders have said they're not interested in having nuclear weapons. They have said that nuclear weapons are immoral. The Supreme Leader, Ayatollah Khamenei actually issued a fatwah saying that these weapons are, indeed, immoral.
And I guess, it's possible they could just be lying. But it does seem odd that a country that the Islamic Republic that bases its legitimacy on being a guardian of Islam that would develop weapons that it considers immoral. That would seem to undercut their own legitimacy.
MULLEN: Well, I think that speaks to the importance of the dialogue that President Obama has stated he wants to initiate and to really wring out, whether that's how the Supreme Leader feels. Certainly from what I've seen, Iran on a path to developing nuclear weapons.
STEPHANOPOULOS: So you don't believe it? That they don't want nuclear weapons.
MULLEN: At this point no.
STEPHANOPOULOS: And the chief of staff to Israel's defense minister, General Michael Herzog, has said that Iran could actually have its first nuclear weapon by the end of 2010 or the beginning of 2011. Do you agree with that?
MULLEN: Well, I think you make certain assumptions about what they can do. Most of us believe that it's one to three years, depending on assumptions about where they are right now. But they are moving closer, clearly, and they continue to do that. And if you believe their strategic intent, as I do, and as certainly my Israeli counterpart does, that's the principle concern.
STEPHANOPOULOS: And you just said that you believe that a nuclear Iran would be calamitous for the region. But last year, Sy Hersh in the "New Yorker" reported that you pushed back very hard against any notion of a military strike during President Bush's administration. And you've spoken publicly about the unintended consequences of a military strike by Israel. So what worries you more? A nuclear Iran or war with Iran?