Interesting interpretation by Paul Rogers in Open Democracy:

The discussion about the withdrawal of troops from Iraq, however, is a masquerade. The real project for the United States administration over the next few months is to present to a domestic public the idea that the US is starting a pullout. The deeper reality is what even a relatively small evacuation of troops may signify: a change in the US’s strategy in Iraq and a turn to the “plan B” described in earlier columns in this series (see “Iraq: thinking the unthinkable” [30 June 2005] and “Planning for failure in Iraq” [15 September 2005]).

What “plan B” amounts to is large-scale disengagement from Iraq’s main urban settlements, leaving these either to Iraqi security forces under government control or (in many areas) an increasingly powerful group of Kurdish or Shi’a militias that have the capacity to enforce control by often brutal methods – including detentions, torture and death squads. Meanwhile, US forces would concentrate on building and defending a series of major, well-protected bases outside urban areas, using helicopters and strike aircraft in support of the Iraqi government of the day. Now that militias work closely with Iraqi security forces – to the extent of infiltration and even takeover – this scenario means that US air power may well end up indirectly supporting such militias.

The quiet pursuit of this alternative strategy has seen the US armed forces constructing the appropriate facilities on a massive scale – not least at Balad, where the helicopter base now being prepared by the KBR company will approach the size of some of the largest bases in Vietnam during the American war there.

The result of this approach, if and when it is followed through, will be twofold: US leaders will be able plausibly to present to their citizens the impression that the Iraq war is beginning to wind down, and they will make any Iraqi government fundamentally dependent on US military power for its survival.

Which, I guess, would mean they would be co-operative over the matter of oil supplies…