Total War......not a good idea when you don't want to anger a dozen other nations, beside the one you are fighting.
Weren't they already mad? Total War is how you win wars. There are many books written on how Sherman's march to the Sea where he just butchered southern town after southern town was what really broke the will of the South in the American Civil War. In anyt case, that needed to be part of the calculation before deciding to resume the war after it had been on pause for so long.
Difficult for the US to have any allies in the middle east if it started decimating the population of the countries they invaded.
Unless you threaten to decimate them too. According to President Musharafs book, that is exactly what the US government told him to get Pakistan's help in Afghanistan.
Look, I'm not arguing for or against the Iraq war. I'm telling you how it could have been won. Past tense. From where the US is at now, I don't know where they go. But I know what civilizations do to win wars against other civilizations. It is not PC to talk about anymore ("Politically correct" an invention of the 60s).
Besides, looking at it from an historical and localized view, the Middle East, since the times of the Romans, have never truly being united under one goverment/leader. The people there, historycally, are not easily controlled by any foreigners.
What about the Ottoman Empire?
Look, people will follow any order, convert to any religion, conform to any morale code... etc. if you kill enough of them first. How many depends (historically speaking) on how different what you are trying to force on them is from what they had. Protestants vs. Catholics during the Renaissance?
Generally speaking, a civilization's will seems to break (from my own research) at about 6% to 12% casualties... although in some cases if you are attempting a radical change you may have to get closer to 20% casualties before the civ's will is broken. REALLY broken. Less casualties and you just lead yourself open for another war later or continued revolution.
The more interesting question is what will the Geneva Convention do to the West if it continues to fail in vigorously destroying its foes. I don't think nuclear weapons are the end of war. I understand the GC's goals are to encourage "gentlemenly wars" that move away from the millions killed during world war 2. However, things like the prohibitions from killing civilians, I think makes following the convention and winning a war at the same time almost impossible. The Convention rightly recognizes that the killing it TAKES to win a war is horrible and should be avoided.
In fact, IF the US falls from becoming a super power soon, it will be (IMO) because it fails to ever actually use
its power when seriously under threat because it tries to follow the Convention - combined with an economic collapse due to unchecked inflation and a fluid currency no longer backed by real value. THAT can only happen if the dollar stops being the reserve currency however... which is why the US should be worried about the Euro. Not the EU, just the Euro.
But I'm getting distracted. The point - my response to the original "if we are so great why didn't we..." question is: no matter your country's military ego, it doesn't help you WIN WARS unless you kill people. Millions and millions of people.
If you don't like that, don't get into wars.