The Hatfields and McCoys were rival American clans who feuded in the latter part of the 1800s. They lived on opposite riverbanks and dealt in moonshine.
The Shiite clans of South Iraq are having family feuds and the new government and its occupiers have been unable to settle them down. It took negotiation from Iran, because clan ties predate national borders.
Imagine if aliens from another planet had come to the US in the 1800s to intervene between the Hatfields and McCoys! Ironically, in 2003 they united against their common enemy, "the perpetrators of 9/11." check out their next reunion plan here.