I think the difference here is that the war is still being fought, and that there is still time to alter our strategy in a way that makes up for past mistakes. That strategy doesn't involve withdrawal at all (a disasterouss move and an insult to the Iraqi people), but it does involved a drastic reassessment of the resources we're willing to deploy.
The war is not being lost, but isn't being won either. It's just goin on... and on... and on... Tours are going twice, three times in some cases... Patton said he didn't like paying for the same real estate twice, and yet due to Rumsfeld completely underestimating the troop strength required to maintain stability in postwar Iraq (despite the warnings of his uniformed staff), US forces are paying for the same real estate several times in the same week! They sweep an area clean of insurgents, but have barely moved the Bradley's out before the jihadists are right back in there again (the IDF knows exactly how that feels; not terribly good for morale). It's brutally inefficient, but it isn't changing.
After much huffing and puffing, the Pentagon finally agrees to send an extra 20,000 men (frankly, it should have been 200,000, and it should have been two years ago). Of course, increasing troop levels now is arguably a too little too late. They should have done it when popular opinion was still vastly pro-occupation. But people are getting tired and restelss about the whole endeavor. Especially now that the President has gone on record to say that there are no WMDs in Iraq, AND contradicted his own VP by stating that there was never any evidence that Iraq was behind 9/11 either. For good or ill, a lot of people were for the Iraq war precisely for one of these two reasons (few were in it for humanitarian reasons; humanitarian reasons usually associated with the questionable foreign policies of Clinton).
Soldiers on their second and third rotation are also starting to get sick of it. They can't win on the ground because at any one moment the best they can do is police the ground that their walking on.
IMHO, Bush should have accepted Rumsfeld's resignation the last time rounds. Rumsfeld spoke about having 'to go to war with the army you have' - quite right - so why did he choose to go to war with half the army he had? I don't think he's provided a satisfactory explanation for that.
Since I am not in the decision making circle of those who are deciding what the needs are in Iraq at any given point in time, I cannot speak to whether they have miscalculated during any point in the war. It is easy to sit here where we are comfortable and critizise what has gone on over there. I would hope that people in the states would consider that the media and the Ill-Liberal politicians have done their abject best to vilify the President and this war from the very beginning. Our Military has had a difficult time in recruitment as a result of the constant battering in the media on a daily basis from shortly after 9/11/01 to today. If this were the case during WWI or WWII we would have lost both. I agree that the battlefield requires constantly changing tactics. And, from what I hear from those over there, this is what is constantly happening. One of the biggest problems we face is that the enemy hears and sees all the negative media on the war and they believe that they can continue until we "give up". We are fighting an ideology rather than a nation state. In the minds of the enemies we face, they do not care how long this takes for their victory when they believe we will CUT-AND-RUN from Iraq. If we were completely united without all of this partisan bickering from the Ill-Liberals (who hate this President and want go regain power) the enemies wouldn't have such faith that we will eventually quit. Yes, I know there have been Republicans who have also "bitched" about this war. many of these are facing very tough re-election and want to appear to be above the debate. The others are Rhino's.
Change is needed. The first and most important is an end to the bullsh*t comments flying around here in the states.
"But people are getting tired and restelss about the whole endeavor."
The only people "getting tired" about it are the idiots dumb enough to believe the driveby media and the wimps who are politically motivated (don't want Bush to reap the political benefits of a military victory).