Muslims have been fighting non-Muslims for about 14 centuries now. The Muslims largely took over the Middle East soon after the religion of Islam was established in the 7th century if I remember correctly, and they began expanding into Europe, Asia, and Africa. They took the northern parts of Africa and have held them ever since. They took most of the Iberian and Balkan penninsulas. Eventually, they were stopped in both places. Attempts to roll back their conquests have met with mixed results. The Iberian Penninsula was freed of Muslim rule in the 1400's. For the most part, the Balkan Penninsula was freed of Muslim rule in the 1800's although they still hold parts of the Balkans.
Some Muslims no longer have a desire to put the entire world under strict Muslim rule. Many of these are content to have largely secular governments that respect the strict dictates of the religion without forcing them on others. Many of these Muslims have become completely secular and only see Islam as a collection of traditions from their past. Many fall somewhere in the middle.
Unfortunately, there are others who want to destroy or subjugate us just as they wanted to destroy our ancestors a thousand years ago. Some of them may still see the struggle as a deeply religious quest. Others probably just like the thought of having someone to kill and use Islam as a convenient propaganda tool. Others primarily want to kill Jews for whatever reason that some people have an innate hatred of Jews, and they see us as an impediment to their killing.
The point of this trip through history is that these people want to kill us. Some of them were based in Afghanistan for a while. Others are based in Iran, Iraq, Saudi Arabia, Libya, Egypt, and other Middle Eastern countries. They aren't interested in talking things out, and there is no accomodation that we can reach with them. Therefore our options are to continue fighting them on a low level for as far as we can see, to try to negotiate some terms of our own surrender, or to keep hurting them until they surrender or are all dead.
We can't deal with all of them at one time or in the same way. In some cases, it would be better to engage their countymen economically and culturally and let their countrymen deal with them. In other cases, we are in a position to strike a military blow against them. The former way is very good at times and minimizes the shedding of innocent blood. The latter is better for breaking the enemy and making them realize that war with us isn't in their best interest. In Iraq, I think we have a good opportunity to do the latter.
I think the picture you paint of just creating new energy sources so that we won't need foreign oil is unrealistic and naive. May I ask how many college-level thermodynamics courses you have taken? If you well-versed in this area, I'd like to hear you give some specific ideas of ways to harness the "teeming" energies of "the universe." If not, I think you need to look at the issue more closely.
Furthermore, I was not speaking only of energy supplies. The industrial revolution created a need for mineral resources that simply weren't needed in the days of Adams and Jefferson. The most familiar example to me is chromium. There are no worthwhile chromium ores in the United States or really in this hemisphere, but chromium is a vital mineral. It is the alloying element that gives stainless steel its corrosion resistance. Without stainless steels, much of the chemical industry simply couldn't exist. Chromite refractories are also used in much (maybe all) of the steel industry, and without them, we probably wouldn't have any production of steel either.
Would we survive as a nation without these things? We might, but the cost of everything that we use would rise to the point that most people would lose their standard of living. I guess if you want everyone reduced to that point, then advocacy of not ensuring a stable supply makes sense. For the rest of us, ensuring a stable supply of needed materials is a part of protecting the national interest.
While some hold to this romantic notion that expansion and protection of our national interests is against the ideas on which this nation was founded, the fact is that our Founding Fathers recognized the need for the nation to act for its own good. Thomas Jefferson sent the early Navy to attack the Barbary Pirates. He could have left the Mediterranean to European shipping or just told the American ships that they'd have to deal with these people on their own. Instead, he used force against our economic enemies to protect our national interests in another part of the world.
I'm saying that once again we have a national interest in what happens in another part of the world. We need the oil fields of the Middle East to be controlled by people who will be our friends and trading partners. Failing that, we need to control them ourselves.