@oristarA,
Withdrawal is, in itself, neutral. If it is seen as negative, that is an expression of the political point of view of anyone who describes it in that manner. In a purely military sense, withdrawal and redeployment are synonymous. So, for example, in the first world war, in the western theater in Europe, the Germans attempted (and failed) to implement a plan which would have resulted in them taking Paris within six weeks time. The plan did not take into account the simple factor of fatigue (Allied soldiers often had to wake up German soldiers in order to make prisoners of them, and in some cases, just flung the sleeping soldiers into trucks). The plan also called for the Germans to put all of their weight into the right wing, even at the cost of allowing the Russians to overrun parts of east Prussia.
Well, the Germans didn't put all of their weight into the right wing, and the Russians moved faster than anybody would have believed before the war. Troops were transferred from the west to the east at a critical juncture when the commander of Germany's Eighth Army panicked. In fact, these troops were sent east at a time when, using the troops available, the chief of Staff of that army, Max Hoffman, went over to the offensive, destroying Russia's Second Army, and forcing the retreat of Russia's First Army. The retreat of von Rennenkampf's First Army was a strategic withdrawal forced upon him by the collapse of Samsonov's Second Army. Either withdrawal or redeployment would be used in a negative manner to describe Rennenkampf's retreat, but no one with any military sense would fault him for recognizing the necessity of the withdrawal.
Meanwhile, in the west, the Germans did not make the progress toward Paris and the knock-out blow the plan intended, but not just because they had failed to put all of their weight into the right wing--but also because the schedule simply failed to recognize "human frailty." The German troops were literally asleep on their feet at the end of August, 1914. The plan also failed to take into consideration the logistics of moving rapidly in occupied territory--the Germans could not repair and operate the Belgian railways to supply their troops, who were often held up waiting for food and ammunition. By the time of the battle of the Marne in September, 1914, the Allies had been driven back onto their bases of supply, while the German supply lines were stretched to the breaking point. (This is always a classic problem of warfare--a successful commander may move so fast that his own organization and supply lines break down. It's as old as warfare, too--the genius of the Romans was to keep their troops supplied even in the remotest theaters. In his Gallic War commentaries, Caesar always tells what measures he took to supply his army at the beginning of each campaign season. A great leader can often be measured by how well he understands the entire picture, and not just the fighting at the front line.)
When Paris was saved by the battle of the Marne, the armies did not immediately settle down into the lines from which they would fight for the next four years. In the center of the line, the Germans withdrew their troops to a line of ridges known as the Chemin des Dames (literally, the "Path of the Ladies"). This was a very wise deployment, because it forced the Allies to place their troops in lines which were overlooked by the Germans who were now on the high ground. It meant that the Germans could hold their lines with fewer troops, and could command the ground of any attempted attack by the Allies with their artillery. That redeployment, or strategic withdrawal, actually served to improve their position, and to use their assets much more efficiently.
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Someone who refers to a withdrawal from Iraq in a negative manner, as shameful or cowardly, is not expressing a military opinion. He or she is expressing a political opinion.