i think it's a bit of an simplification to assume that overwhelming force can accomplish stated goals of bringing freedom and democracy. If that was ever the serious intention of the war in Iraq, which is also debatable. I'll try to tie this point to the topic of moral relativism.
You can't compare the world wars which took place in Europe, a region made of largely industrialized, civilized technological societies which already had advanced political systems, advances in education, liberty and wealth to wars in Iraq or Afghanistan. First of all, islamic nations which simply means, their fundamental value system is totally different. To them westernization itself is anathema, IE repugnant. It is seen as sinful. Second of all, the people are much more used to living in hardship, living under totalitarian rule in a theocracy. The choice of living in hardship in this life, or conceding to western liberalism and its supposed merits but spending eternity in lakes of fire seems self-evident. This is where relativism comes in, in a way. I can take the harsh life, suffering and cruelty that war brings if I already live in a society where life is cheap, where poverty is normal. OTOH do the same to people here and we cave in quickly. We don't do well if you take away our convenience stores, central heating and flush toilets.
The people of Iraq or even more, Afghanistan could not be bombed into the stone ages because, they are already living in the stone ages. Look also to Vietnam, no amount of carpet-bombing could achieve stated goals.
To me the dichotomy is whether it is even right to use war as an instrument of liberating a third party, in other words war imposed by complete outsiders to bring perceived blessings of a foreign system, by annihilating their cities, killing their families. How is it really different than what any empire has done in the past in expanding their colonies? Does it make sense to bring them death and destruction at such an intense level, gambling on the hope that it shall bring a wonderful future someday, vs. allowing a moderately intolerant, authoritarian society to exist where there is some steady level of violence? Which of us then is not violent?