An argument from history, and why are we in Iraq?

The Monroe doctrine, but even before that colonialism, and before that, Mongol hordes attacking China, and before that, Rome conquering the entire Mediterranean, and before that Greece organizing into a larger collection of city states.
Granted:
One drive of humanity takes the form of a desire to mix, and gain greater things by combining but I ask, why is it that this often takes the form of unnecessary violence?
The economic:
My current frame of mind asks this and attempts to answer with a resounding "nobody planned ahead". So now we've invented the car, and the gasoline engine, and we came to rely heavily
on said existence, that in turn has made us heavily rely on oil.

Now that we have created a society that cannot support itself we are stuck!
we cannot maintain our standard of living using only our own resources. The technology used to create current infrastructure (there are a few exceptions like Whole Foods Market) Does not do the job.
Down to the very core we should examine what resources we actually have, and just work from those resources relying on the pace of technological growth to determine our quality of living. Of course I don't think that this can just be done, everything is a process, but first of all we need to start decreasing imports of essential goods, and put that production back in this country, than we need to examine our resources and start using only those resources.
New technologies should replace old as soon as the old threaten to erode a self-sufficient culture. We neeed to work towards a society/culture that willingly abandons old technology in the name of continued self-reliance.
The Social:
Should we feel responsible for others well being?? Maybe, maybe no. In much the same argument as above I think self sufficiency should be a primary goal for a culture in the social realm as well. If a tyrant takes over a country some people put up with it, some don't and in true style of democracy we should not be in the habit of handing people freedom---people need to get that for themselves. The world knows we exist we don't need to impose us on it. We can live by example. We don't need to force feed the world our ideals if they want them we can send them a book and a copy of our constitution and say "good luck it worked for us, maybe it will work for you too."

So here we are killing a bunch of people half way across the world spending billions of dollars to do it! Because we want them to live like us, like us, and sell us things we need to be perfect examples of what the world should be like.

What a bunch of malarky. Lets take those billions in resources and become self-sufficient, and if that includs lazers in the air to protect our borders that's fine. But defence is not anything that goes beyond our own borders. How can anyone be so feeble minded to not realize that resources spent telling other people how to live is like making your neighbors kid be a vegetarian because you are, nevermind that your neighbors kid is aenemic.
I am very disappointed in any able minded individual who actually thinks military service is doing us any long term good whatsoever. I for one don't like being implicated in the whole mess. I'd much rather see that money go to things that can actually long term help this country, not just get us by for another 25 years. I may be pig headed here but is't totally obtuse to think military action outside of ones own country is in any way beneficial to anyone longterm.
If you notice, I'm using careful wording. I am not against the military I am against what the military is doing right now, civil wars and revolutions and even border disputes happen and military might is important for those reasons.
You ask about those poor people getting killed in other countries by dictators and such. well, We shouldn't be happy about it but at the same time these types of situations really need to be handled by a world wide governing board-- perhaps the United Nations. Some entity that lays out guidelines for how government is allowed to govern. Soverenty of a nation is encroached upon by such standards---but isn't the act of invading a country just to get rid of it's leader the same thing? I just would feel better with an entity that makes guidelines not just some big country that determines how other countries should govern.

I'm not sure where this rant actually ends but I hope it leaves one with a feeling that they should work on making this country self-sufficient and non-meddling but friendly.