Philosophically speaking, if Iran and Iraq had a huge war between themselves all throughout the 80's, isn't it logical to assume that at least part of the "insurgency" in Iraq is coming from Iran?
Is the border between Iran and Iraq completely open, partially open? The Iran Contra controversy of the 80's has been reborn, and the various SAME players are probably profiting from Iran's involvement in Iraq's affair.
It seems strange to think of people in the U.S. profiting somehow by supplying weapons to the region while also trying to create "peace" and "democracy".
It just seems to me that unless the United States is willing to put up some kind of wall between Iran & Iraq, the insurgency will go on forever because it's much cheaper for Iran to fight this kind of war then one in which they militarily fight Iraq in the open.
A documentary on the Iran Iraq war, that really goes into detail as to what happened in the 80's, would probably shed light as to what is going on now.