Predating the first post at this present blog by about 13 months in 2006 the documentary A Crude Awakening warned of the implications of oil soon running out.
From Wikipedia’s section “Findings”, my emphasis:
overall conclusions were that a global peak was imminent (if not already occurring), more wars would be fought to control access to oil resources, and economies most dependent on oil (or relying on trade with oil-dependent nations) would suffer dire consequences
At IMDb the user cross-45 rates it 10/10 and from his review:
This film puts into perspective and also gives me many answers for the bloodshed carried out in many of the wars of the last century, and continuing into this century
Already in the trailer, a woman says:
Oil is a magnet for war. Oil starts wars.
Welcome to my Ecowar Movies list (and my ‘Must See’ list), A Crude Awakening.
See IMDb, the Wikipedia entry and the official site. (Thanks to Lara Smallman for alerting me about this one.)