Nevertheless, even if we set the economic aspect of the matter aside a shift to another energy source would put a serious strain on international relations between exporters and importers of oil. Even at the present moment relations between the US and OPEC countries aren't too rosy, imagine what would happen if the vital oil relationship ceased to exist...

Funny thing is that sooner or later we'll have to go ahead and abandon oil just because we won't have any more of it left. Then it will present a much harder blow to both economic and political life than if the new source was introduced gradually. However, currently, no one is willing to even consider the gradual implementation of a new fuel as viable. Car producers have their long-term contracts with engine producers, politicians have their trade arrangements with oil-exporting countries, and people aren't too unhappy with €1.5 per liter of unleaded so I guess we're stuck with the current situation... at least for a while.