In one brief moment, Saul Loeb has managed to encapsulate Iraq. Six years ago, Bush took down the Iraqi government to save the poor defenseless people of that country. Now the situation is exactly reversed. Poor defenseless Bush requires the Iraqi government to protect him from its people. There aren't many photos which can communicate such clear symbolism without any fluff.
This photo is somewhat unusual for me. Usually I pay little attention to what is in a photo. I'm more concerned with the photo itself. I'm a sucker for form, composition, color, framing, synchronicity, the things that distinguish an image of reality from that reality. I won't say I'm completely in the Winogrand camp of "The only thing that matters is the photograph" but I definitely lean toward that outlook. But with this image none of that seems to matter. As a photo it's not particularly noteworthy. If the two people were not Bush and al-Maliki the photo would be worthless. But that's just the point. In this case the actual content of the photo makes it a strong image.