Übergeek 바둑이:   Great post.  I only take small issue with a few things.  I think it may amount to perspective.  Truth gets muddled in opinions and bias.  I admit a bias toward the US and consider its intentions in the world noble.  Not always, but more often than not.

"We get to the heart of the matter. We MUST do something. What if we
didn't? The thugs would run over things. Yet to stop the thugs we must
become thugs ourselves."

Thugs or knights in shining armor?  Here it's a matter of perspective.  If we oppressed the people or ran over them to get to the thugs, then I'd fully agree.  But generally speaking, the US does not act in this way.  The US policy is to go after the thugs and kill them.  When we vacate Iraq we will leave it with better hopes for the future and freedom from the trannical dictator that murdered his own people.  That's called liberation.  Yet the events in Iraq are often characterized as an invasion.  Again, it's perspective. 

The US is often like the guy in the store who witnesses a robbery.  A man in a mask points a gun a the clerk, pistol whips a customer and threatens everyone.  The "US guy (well call him gUS) sees an opportunity to deal with the thug and jumps him.  There's a fight.  gUS gets away the gun and shoots the guy (who was still fighting) five times - point blank.  gUS wanted to fully end the threat.  gUS was just in the store to buy some gum.  He likely saved the lives of people in the store.  But the press (the world) reports the story, not as gUS being a hero, but as gUS being a thug.  The world complains that gUS acted reclessly putting everyone at risk.  And gUS, while in possession of the only weapon, fired point blank into a "defensless" man, killing him.  gUS is now a villan.  The hero is the thug (this is exactly what is happening with captured terrorists). 

" We want to save the world, and use force to do
it."

Because that's often the only way to do it.  

"We want to have it both ways. Go to war and impose our system on
others, but we want to be called lovers of peace and democracy at the
same time. Our politicians know this and they try their best to
convince us that the idelogical justifications are what matter. The
ulterior motives (like oil and power) should be ignored."

or

We don't want to have it both way.  We go to war, sacrifice our lives to give other nations the opportunity to develop a system of freedom.  We are loves of peace and often the road to true peace is at the end of a gun (can you name any long lasting peace that hasn't required a threat of some kind?). 

As for the comment on politicians:  I don't trust most of them. 

On oil:  I'm not convinced that it's all about oil.  But I'm also not convinced that oil isn't on the table.  But it's not the only thing.   World conflicts are often far too complicated to boil down to any one thing.  There are many factors and suggesting it's this thing or that thing is mostly guess work.