Despite conflicts in Syria, Iraq, Nigeria and Libya, oil prices have bottomed out since June this year. Falling by more than 20 percent, this phenomenon seems somewhat surprising given that many forecasts predicted otherwise, or thought at least that the oil price would remain close to its $100-per-barrel line.

No wonder commentators are oscillating between different storylines, trying to explain what's currently happening. One is what I will call the "economic downturn story." The other is the "Russian-Iranian conspiracy theory."

Economic Downturn Story

The economic downturn story is obviously the simple story of decreasing global demand and increasing supply of crude.

In October, the IMF published its global growth forecast for 2015, predicting a dire picture of continued economic stagnation in the face of reduced manufacturing output by Germany, falling Chinese growth and Japan entering a year of lower-than-expected growth. All this could have led speculators to expect falling global demand.

On the supply side, the U.S. shale oil renaissance has lifted U.S. crude oil production from a low of about 5 million barrels per day in the mid-2000s to a 20-year high of about 8.7 million barrels per day. In addition, Libya opened its ports again, and Saudi Arabia seems to be committed to maintaining a market share by pumping up its production.

Thus, prices fall.

Russian-Iranian Conspiracy

For others, all of the above explanations seem doubtable. Why should oil prices fall exactly now? U.S. oil production been on a continued high since last year, and global growth has been in stagnation since the financial crisis or at least since the beginning of this year.

Commentators, like Thomas Friedman from The New York Times, think that we are witnessing a global turf war between Russia and Iran on the one side, and the U.S. and Saudi Arabia on the other side. According to Friedman, what Saudi Arabia and the U.S. are currently trying is basically the same they did with the Soviet Union right before the fall of the wall — trying to pump Russia and Iran to death.

The story goes that over the last months the U.S. and particularly Saudi Arabia have increased their production. The U.S. just started to export some of its shale condensates in June, while Saudi Arabia has refused to cut back its production and keep its market share among the OPEC members. Surprisingly, the oil giant has also announced a drop in its supply prices to Asia and the U.S..

As Stanley Reed notes in an article in The New York Times on Oct. 3: "Saudi Aramco, the national oil company, stunned markets by announcing that it was cutting prices by about $1 a barrel to Asia, the crucial growth market for the Persian Gulf producers, as well as by 40 cents a barrel to the United States."

Rising oil supply hit Iran and Russia hard, especially in times of sanctions and an economic downturn. Iranian President Hassan Rouhani calls the fall in oil prices a "plot" on his website, while the Russian newspaper Pravda published an article with the headline "Obama Wants Saudi Arabia to Destroy Russian Economy," on April 3.

In retaliation, Russia announced helping Iran to construct new nuclear reactor on Nov. 12 so much for the upcoming nuclear talks with Iran.

What speaks against this conspiracy of course is that a fall in oil prices would not be the long-term interest of the U.S. Extracting shale is costly and will hit U.S. production at some point. What this would mean is that oil prices are bound to rise again.