Do you not think that the United States (and any other country for that matter) hasn't progressed down this same path?

The competency of any military assessing world petroleum reserves and consumption is enormous! Petroleum is the achillies heel of an army. Petroleum is probably the single most valuable commodity for maintaining any army's fighting posture in this day and age. With maybe water and food being a close second.

But remember, petroleum must be continuously and logistically transported to troops fighting on the ground or in the air. You can't just locally procure a sustainable petroleum source for an army on the move.