I've had to go round about with a few arguments both pro and con about leveling a city in such a fashion.  Its not an easy thing to consider and I'm not suggesting the idea in a off the cuff cavalier way, but it does get a point across.  Also I'm not saying that leveling a city in every instance of war is the move to make, but against Islamic Extremists who respect and respond to naked raw power, its something I think needs to be considered.

One of the problems I think exists with modern warfare (that is war after WWII), is that the countries who are striving to keep peace amongst civilizations have tried to bring civilization to war.  War by its definition is a most uncivilized practice.

Tyrants and dictators have become less and less afraid of becoming aggressors and brutal killers.  I think a lot of this is because they know the UN, and those nations which give the UN its muscle(as little as that is) won't fully prosecute a war to its most terrible conclusions.  They hide behind the very rules of war we(Europe and the US) formed after WWII to try and limit civilian casualties.  This puts civilians directly in the path of harm as they become human shields.

I sometimes wonder if more civilians would be spared if we just made it a point to all aggressors that if they violate the rules of war, then we toss them also, and show true unrestrained destruction upon them and their armies.  Problem right now is we keep our hands tied while they fire Anti-Aircraft guns beside homes, or take up sniper positions from inside family's houses, or launch rockets from beside a UN watchpost, or suicide bomb markets, and disco studios.

They know we will play by the rules even if they don't.  And in their minds us staying by the rules is not a sign of strength and humanitarian restraint(as we view it), it is viewed as weakness, and an exploit in our armor.  And they will keep picking out at that chink in our armor until they finally cause us to seriously bleed or die from it.