Anbar province in Iraq was, until recently, the "wild west" of Iraq. Two years ago, there were 500 attacks a week against Iraqi and U.S. forces in Anbar. A year ago, there were 40 a week. Now, there are only 3-4 a week. The main reason for the decline is the defeat of the Islamic terrorists and Sunni Arab nationalists who were responsible for most of the violence. The enemy here was either killed, forced to flee Anbar, or made peace with the government.
This large, mostly desert, region of western Iraq has long been dominated by over a dozen Sunni Arab tribes (about 1.2 million people). Even Saddam Hussein handled these tribes gently, and made them well compensated allies after the 1991 Shia rebellion. But the people of Anbar are among the poorest, and least educated, of the Sunni Arabs who have long dominated what is now Iraq. The much wealthier and well educated Sunni Arabs of Baghdad looked on the folks out west as a bunch of desert bumpkins.
Al Qaeda, and several Iraqi terrorist organizations, set up bases in Anbar in 2003. This led to several major battles with U.S. forces (Fallujah, Ramadi) that forced the terrorists to keep their heads down, but did not drive them away. As early as 2004 the terrorists began having problems with the locals, who quickly tired of living in the middle of a war zone. By 2005, some of the Anbar tribes were openly fighting the terrorist groups. As a result, the terrorists had to spend more and more of their time trying to keep their Sunni Arab base in line. The "red-on-red" battles between Sunni Arabs, that U.S. Marines first noted two years ago, increased month by month until the terrorists were gone.
There are 72,000 troops and police in Anbar (one third each for U.S. Marines, Iraqi Army and locally recruited police). There are also over 20,000 armed men in tribal militias who are now hostile to any Islamic terrorists they might encounter. And there are still al Qaeda, and other types, of Islamic terrorists there as well. It's expected to take another year or so before all the terrorists are found and killed or arrested. The U.S. troops are already leaving, and being replaced by Iraqi troops (mostly Shia) and police (mostly local Sunnis). The three years of intense violence have left the locals with memories of something they don't want to repeat.