Steven Simon, (at the Council of Foreign Relations) has an important article in Foreign Affairs describing the real effects of the surge and related US policies.  Its implications are disturbing, especially when you couple them with the current reality of Baghdad: segregated enclaves behind concrete blast barriers currently protected either by Iranian backed militias or the US, and a President who Petraeus himself has admitted is an Iranian agent of influence.

I recommend reading Simon’s article:  `The Price of the Surge`
http://www.foreignaffairs.org/20080501faessay87305-p10/steven-simon/the-price-of-the-surge.html
 
but for those of you who don’t have time, the most important thesis of his essay is, in his words, that `The Bush administration's new strategy in Iraq has helped reduce
violence. But the surge is not linked to any sustainable plan for building a viable Iraqi state and may even have made such an outcome less likely -- by stoking the revanchist fantasies of Sunni tribes and pitting them against the central government. The recent short-term gains have thus come at the expense of the long-term goal of a stable, unitary Iraq.’

The Sons of Iraq, (Sunni tribes, warlords) there are about 90,000 of them, are paid for by the US at $360 each per month – DoD estimates a cost of $150m for the year.  They get weapons and logistical support as well.   So the result has been a drop in violence – which McCain likes to present as the US winning and, since US soldiers aren’t being killed,  no harm in staying ad infinitum.

But, Simon  points out, the US has achieved this transitory success  “by stoking the three forces that have traditionally threatened the stability of Middle Eastern states:
tribalism, warlordism, and sectarianism. States that have failed to control these forces have ultimately become ungovernable, and this is the fate for which the surge is
preparing Iraq. A strategy intended to reduce casualties in the short term will ineluctably weaken the prospects for Iraq's cohesion over the long run."
There follows an interesting historical perspective of tribalism and the ways in which different `powers` - be it the British, Saddam,  have tried to manage it.  But the conclusion is clear:
"U.S. strategy is violating this principle by
fostering the retribalization of Iraq all over again. In other
countries in the region, such as Yemen, the result of allowing tribes
to contest state authority is clear: a dysfunctional country prone to
bouts of serious internecine violence. Such violence can also cross
borders, especially if neighboring states are willing to use the tribes
as their own agents. Pakistan provides a particularly ominous example
of this dysfunctionality: its failure to absorb its Pashtun population
has threatened the viability of the Pakistani state. The continued
nurturing of tribalism in Iraq, in a way that sustains tribes in
opposition to the central government rather than folding them into it,
will bring about an Iraqi state that suffers from the same instability
and violence as Yemen and Pakistan.

U.S.
officials in Iraq have taken note of how the current U.S. approach has
exacerbated the dangers of tribalism. Last month, a senior U.S.
military adviser conceded, "We're not thinking through the impact of
abetting further corruption and perpetuating tribal power." In
December, a U.S. diplomat warned, "The absence of government in a lot
of areas has allowed others to move in, whether militias or others."
The net effect has been a splintering of the country rather than the
creation of a unified nationalist Sunni front that, having regained its
confidence, would be prepared to deal constructively with Baghdad."

Simon describes how the support for the Sons of Iraq led to them developing a false sense that this equated to US support for Sunni control of Iraq - and now they've woken up to the fact that this isn't the case, that Shiite dominance is going to be set in stone, the US is again going to be their target.

And in Simon's words, "When it withdraws from Iraq, the United States will be leaving a
country more divided than the one it invaded -- thanks to a strategy
that has systematically nourished domestic rivalries in order to
maintain an illusory short-term stability."

He sees one plausible consequence as being the rise of the military, (the one trained by the US)  -

"the United States would be confronted by a strong, centralized state
ruled by a military junta that would resemble the Baathist regime
Washington overthrew in 2003. Rather than an anarchic situation, the
United States would face potentially aggressive nationalism and a
regime unsympathetic to U.S. regional priorities."

(You have to read the entire article yourself to do it justice)

His conclusion is that there is no good option in Iraq but that the US must abandon its current `bottom up` policy of supporting the Sons of Iraq;  that it must commit to a phased withdrawal and cede some of its control in Iraq:  only insodoing, can it persuade surrounding countries and its
European allies and the UN to cooperate to facilitate a `reconciliation process in Iraq`.  He believes that in the absence of a US plan to withdraw there is no incentive for allies to get involved.
There's plenty more in the article  -   I recommend it.