Saudi Arabia wanted the USA to intervene against ISIS. The USA wanted the price of oil the fall to hamper Russia and Venezuela. Russia because they are getting aggressive and doing things in the Ukraine and Syria that we don't like. Venezuela because they are the center of anti-Americanism in South and Central America.
Which is exactly what happened. We bombed ISIS. The price of oil fell. Russia and Venezuela have been hurting.
There will likely never be proof whether this theory is correct. But leadership in both Venezuela and Russia have come out with the same theory. Articles like http://www.nytimes.com/2015/02/04/world/middleeast/saudi-ara... make it clear that the USA and Saudi Arabia are playing the geopolitical angle with Russia. And our current efforts to normalize relations with Cuba sure looks to me like an attempt to strip Venezuela's closest ally away from them.