Contrary to what many decision-makers in the West think, this is not a power struggle between good guys (Fatah) and bad guys (Hamas). This is a power struggle between bad guys and bad guys. Hamas and Fatah are not fighting over which party is going to bring democracy and a better economy to the Palestinians. Nor are they fighting over building infrastructure and good government. Instead, these two parties are fighting only over money and power. The real battle between them is over who is going to control the billions of dollars in financial aid that the Palestinians are continuing to receive from the US and the many donors in the West.
http://www.hudsonny.org/2009/07/the-hamas-fatah-war-bad-guys-vs-bad-guys.php