This is a good article at GlobalResearch on the geopolitics of pipelines. I personally believe that the US presence in Iraq and Afghanistan is ALL and ONLY about energy politics.
Check out the article then follow the news. It is amazing how pipeline maps (existing and proposed) explain and predict US military engagements.
Additionally, it is amazing how terrorism is suddenly "discovered" to be a big problem in places that have untapped oil, gas, and/or mineral reserves, such as Yemen.
Why is the U.S. AFRICOM expanding? The answer is clear. There is a big resource grab happening in Africa. Michael Klare's book, Resource Wars unpacks these trends.
What is so problematic about the resource grab is that the money and labor spent on colonial control and military conquest could be spent developing more sustainable energy platforms and forms of living....
What is worse, US interference in resource rich nations disrupts lives, livelihoods, and national self-determination