Americas Global War on Terrorism

I got into an interesting conversation with my brother Sunday. We were discussing Americas involvement in the wars in Afghanistan. His argument was that the sole purpose of our presence there was to control the oil in the area. I tried to explain to him my belief that our involvement there is because of Americas commitment to Globalization and World Empire. I told him I thought that our presence was mainly to establish military, economic, political and cultural centers of power within that region. I told him I thought America was putting forth a concerted effort to isolate Iran. He strongly disagreed and continued to support the idea of oil being the main cause of conflict in the Middle East.