[pyvpx]

the US can't let that happen because the hegemony the dollar has over the world economy would be at a very high risk. Oil is traded in Dollars exclusively. This gives the Dollar some very powerful and unique powers. Saudi Arabia has a strong hold on the OPEC cartel.

[throwaway1892]

If oil stops being so important to the world economy (which might happen, but not right now), this would reduce the risk to the world economy. And as oil loose its importance, the OPEC cartel will weaken (also OPEC do not contain all oil-producing countries).