Ambers explains the administration's view on consistency:
It's quite possible that a variant of the failed strategy in Iraq -- primarily counter-terrorism + bribery + a war of attrition over the resources (substitute poppy for oil) might work better in Afghanistan. If Obama decides to go this route, and it looks like some influential folks are beginning to favor it, he will have backed away from what one might call a campaign promise to resource Afghanistan properly. That doesn't get you points in politics. For some reason, everyone obsesses about consistency, which this administration believes is just about the worst value to hold when it comes to foreign policy.
To them, consistency is dogma. In their view, the U.S. ought to treat situations differently because they are different, because ceteris paribus never applies, because situations are always evolving, because interests are always more pressing than values. The downside of flexibility is that it comes at the cost of legitimacy. But so does does dogma, magical thinking, a blind faith in whatever patterns we think we see in the void. I don't know if Brent Scowcroft would call this approach "realism." It's more... ad hoc.