You think Iran is supporting or controlling the terrorists?

Pro: Iran has no interest inending the terror in Iraq. It keeps the US troops busy. Furthermore the Iran hates the US and the presence of the US troops there. And they would be pleased to create a religious system in Iraq.

Con: They know that their situation is dangerous. Every contact with terrorists will be a reason for the US to attack.

Resume: I do not think that the Iranian government supports the terror in Iraq. However, Iran society is very inhomogeneus. There are probably groups that are willing and able to deal with terrorists.

What about the other groups:
AQ, fundametalistic moslems, Saddam followers, Iraqi patriots ...?
Which groups are currently operating in Iraq? Is there a common comand or coordination. Or are these groups independently? What is the US strategy? How can other nations help?