Hydra

Perhaps the American and Iraq provisional government should have taken note of the myth of the Hydra Lernaia that was presented at the Athens opening ceremony.

“The second Labour which he [Herakles] undertook was the slaying of the Lernaian Hydra, springing from whose single body were fashioned a hundred necks, each bearing the head of a serpent. And when one head was cut off, the place where it was severed put forth two others; for this reason it was considered to be invincible, and with good reason, since the part of it which was subdued sent forth a two-fold assistance in its place.” –Diodorus Siculus 4.11.5

As Juan Cole points out, every time the United States and the Allawi forces attack the Mehdi army of Moqtada al-Sadr, they inflict heavy casualities not just on al-Sadr's fighters but also the civilian population. However this just makes Moqtada al-Sadre more popular and their is plenty of young dissatisfied shiite men to replace the hundreds that have been killed.