The Persian Gulf produces about thirty per cent of the world's oil, while holding more than a half of the world's crude oil reserves. The geographical concentration of the most important energy resource that holds the world's contemporary technological standard, puts this region in a very important place for the geopolitical options for all countries in the International System. However, the Persian Gulf is a political unstable region in the world, in less than thirty years was involved in three international wars: in the eighties The Iran-Iraq War, in the nineties The Gulf War and recently The American Invasion of Iraq. These conflicts were known by the use or by the threat of use weapons of mass destruction (WMD), and by the heavy casualties in the countries involved in the war. This dissertation analyses the American participation in these three conflicts taking as referential geopolitical concepts, once the specificity of the region demands the rebirth of this discipline that was so often forgotten in the international analyses. The geopolitics emphasize the geographical impact over politics, so the oil reserves in the territory of the Persian Gulf, the energy heartland, will influence the relationship with the others States in the International System. This study examines the American geopolitical options for the region, once a secure access to Persian Gulf is America's national vital interest.