To admit defeat in Iraq is to admit that Saddam Hussein was right; that Iraq is not going to welcome a long-term ("permanent" is a word that can't be used because the DoD has proclaimed that the U.S. maintains NO permanent bases on foreign soil--they are all there as guests) U.S. military presence, even if its operations have nothing to do with Iraq.
The supposed sectarian warfare has to be suspect for several reasons:
1) it was announced as a possibility at the time of the invasion in 2003
2) sect is not an identifier like color. There does seem to be a connection between people's names and their religious persuasion, but the reason people's names are able to be known is because the American occupation has insisted on everyone carrying identification cards.
3) car bombs, the frequent weapon of choice in urban centers, are the trademark of the forces that relied on them to try to destabilize the Saddam regime. Moreover, since cars are easily traced and even prohibited from moving around, you'd think that after four years the car problem could have been solved.

The resistance is targeting Iraqis for elimination. But most of those are collaborators with the occupation and properly seen as traitors.

It's been my postition that mayhem would have to be caused until the Iraqi people cried "uncle" and agreed to the bases being manned and the embassy being a big espionage enclave.

You know, everything would have worked out as planned, if the UN hadn't stepped in and said the country couldn't be run and its minerals sold until there was a duly elected government in place.

Indeed, everything would have been a lot simpler, if George the First hadn't stabbed Saddam Hussein in the back by letting him claim Kuwait and then lowering the boom. Certainly from Iraq's perspective it made sense that if the U.S. was going to have military bases (some the size of Manhattan), Iraq should be able to add Kuwait to its jurisdiction.

So far there's been no official admission that the bases for missile defense are the sticking point. Bringing up the issue by making reference to such facilities in Poland and the Czech Republic (to counteract the Iranian threat!) was a non-starter. Surely Russia and China know what those bases are being prepared for. Rumsfeld himself asserted early on that the bases would be different from those in West Germany because the techs would be on short rotations and wouldn't be bringing their families to the desert.

A good question to start the discussion would be to ask what the hundred thousand troops who never leave the bases are doing there. It's clear that the 50+ thousand combat troops are supposed to provide security for the perimeters of those facilities until the Iraqi military is prepared to do so.
Why else would the first task for a democracy be setting up an army?