Why no one can win in Iraq

From Washington, DC think tank:The Cato Institute; July/August Policy Report by Ted Galen Carpenter:
The war in Iraq is vastly more complex than a civil war.
This is a "struggle of all against all -- a fight among various factions within the Sunnis and Shiite communitise and criminal gangs that have no particular ideology but are taking great advantage of the violence."
This calls for USA to referee a multisided civil war. He writes, "I cannot think of a more utterly futile and thankelss task than that."
One allegation is that if we leave Iraq, al-Qaeda is going to gain a safe haven, and it will be just like Afghanistan before 9/ll. "That is actually the LEAST likely danger." Al Qaeda has a grand total of about 1,300 fighters in Iraq today, compared to the thousands it had in Afghanistan before 9/11. That friendly government protected them.
"In Iraq they will have nothing of the sort. The government is dominated by Kurds and Shiiites who are almost unanimous in their hatred of al-Qaeda." Citing a poll by the University of Marylalnd: "Better than 99 percent of Shiite and Kurdish respondents had a negative view of al Qaeda."
Al-Qaeda does not have a good reputation even among Sunnis,k is supposed allies in the country. That same poll found that 94 percent of Sunnis had a negative view of al-Qaeda.
"Where is al-Qaeda going to gain protection when the organization is so widely hated in Iraq?
At best, al-Qaeda would havea harried existence in a few isolated areas of Iraq, where it might find a handful of allies among Sunnis who are still willing to support the organization after its indiscriminate violence against Muslilm civilians."