TSR: "You cannot protect the Green Zone..."
WOLF BLITZER: A shattering blast in the heavily defended heart of Baghdad stuns the visiting United Nations chief. It comes as critics are raising new questions about the Pentagon's lack of planning for the war in Iraq.
Did that put a vast arsenal in the hands of insurgents?
CNN's Michael Ware is in Baghdad.
But let's begin with our senior Pentagon correspondent, Jamie McIntyre -- Jamie.
BLITZER: Jamie, thanks for that.
And as you saw, it was a truly terrifying moment today for the United Nations Secretary-General. But an everyday fact of life for residents of Baghdad.
So what does that say about success or failure for the mission in Iraq?
Joining us now in Baghdad, our correspondent Michael Ware. Michael, there was a huge scare earlier today.
I want to play this little clip of what happened when the United Nations Secretary-General was in Baghdad with Nouri Al-Maliki, the prime minister.
Let's watch it.
(VIDEO CLIP OF EXPLOSION)
BLITZER: Well, you see Ban Ki-moon, the U.N. Secretary-General. He is clearly startled, as he should be. In contrast, Nuri Al-Maliki, he's pretty cool, calm and collected.
Give our viewers a sense of what this videotape and this sound says to you, someone who's been there for four years?
MICHAEL WARE, CNN CORRESPONDENT: Well, it's obviously, of course, Wolf, that the U.N. Secretary-General is new to Baghdad, because this is an extraordinarily common occurrence throughout this capital.
I mean this happens in people's neighborhoods -- mortars lobbed without warning, rhyme or reason -- let alone the international zone, which is the heart of the U.S. embassy and the seat of the Iraqi government, which is headed by Nuri Al-Maliki.
We've seen on several occasions when insurgents have taken opportunities such as this during press conferences, just to throw the odd mortar or rocket into the international zone or the green zone just to let people know where they are.
Look at the play they're getting from just a couple of simple mortars. I mean the reverberations from that one moment are spinning not just across the country, but across the world. And it's extraordinary to see Nuri Al-Maliki almost holding his political fate there in its hands as he refuses to flinch while the newcomer Secretary-General is obviously in quite some distress -- Wolf.
BLITZER: What struck me was that four years into this war, and certainly several weeks into the major security crackdown in Baghdad, the insurgents can still lob a mortar into this highly secure, so- called green zone, especially timed with the visit of the United Nations Secretary-General.
What does that say?
WARE: Wolf, it says what it's always said. It says it's been this way since the beginning. You cannot protect the green zone from what, in military terms, is called indirect fire -- mortars, rockets and maybe the occasional missile, if they're lucky. They can lob them in from all sorts of directions. Indeed, they can do it from as close as Haifa Street, just a few hundred yards away from the green zone, well within striking distance of the U.S. embassy.
They can do it from across the river in Dora. They can do it from Sadr City.
And this isn't just one enemy, Wolf. This is Sunni insurgents. This is al Qaeda. This is Shia militias. They all lob mortars into the fortified green zone. This is Iraq. You can't protect it. It's the way business is done.
BLITZER: Michael Ware, be careful over there.
And thanks for joining us.
WARE: My pleasure.
Thank you, Wolf.
BLITZER: Insurgent mortars rain death on an almost daily basis. At least 110 Americans have died from mortar or rocket fire since the start of the war. A 60MM mortar has a range of up to two miles with a blast equal to a pound or two of TNT, not enough to penetrate most rooftops.
An 81MM mortar, has a range of more than three miles, with a direct hit likely to contain at least two pounds of TNT.
A 120MM mortar has a much -- is a much heavier weapon, with a range of more than four miles. A direct hit is equal to 10 pounds of TNT and can devastate urban targets.