Are shale hydrocarbons a factor of improvement or degradation of the world energy security?

After having evoked some historical characteristics of the relationship between the USA and Saudi Arabia, the evolution of the world geopolitical and energy context, and that of energy markets, the author discusses the actual geopolitical consequences of the development of the shale oil sector in the USA (a new energy resource for the USA, with impact on the American energy market, but a sector which is finally not profitable), and then outlines that the weak world economic growth adversely affects the shale hydrocarbon industry