Russian President Vladimir Putin heads a meeting with senior military officials at the Defense Ministry's control room in Moscow, Russia on Friday, Dec. 19, 2014. (AP Photo/RIA Novosti, Alexei Druzhinin, Presidential Press Service)

The sudden, dramatic drop in oil prices has changed the world almost overnight. Russia's facing an economic crisis, and U.S. consumers are saving a fortune at the pump. The reasons for the sudden swing are not particularly glamorous: They involve factors like supply and demand, oil companies having invested heavily in exploration several years ago to produce a glut of oil that has now hit the market -- and then, perhaps, the "lack of cohesion" among the diverse members of OPEC.

But now, right on cue, out come the conspiracy theorists including Vladimir Putin — to tell us what's really going on.

Recently, Putin floated the idea that the oil price drop is the result of a U.S.-Saudi plot to hurt his country. "We all see the lowering of the oil price. There's lots of talk about what's causing it," Putin said recently. "Could it be the agreement between the U.S. and Saudi Arabia to punish Iran and affect the economies of Russia and Venezuela? It could."

With these remarks, Putin joined a long tradition of conspiracy theorists who have surmised that the world's great oil powers — whether countries or mega-corporations — are secretly pulling strings to shape world events. Prior oil-related conspiracies abound: 9-11 Truthers and JFK assassination conspiracists alike have sometimes given oil interests or companies an integral role in their theories.

Such thinking has a long history. "During the 1960s and 1970s, when the American conservative movement was taking over the Republican Party, the Rockefeller family was seen as this massive manipulator that controlled America from backstage," says Robert Alan Goldberg, a professor history at the University of Utah author of the book "Enemies Within: The Culture of Conspiracy in Modern America." The Rockefellers owed their wealth, of course, to...that's right, oil.

To understand why oil features in so much conspiratorial thinking, you first need to understand conspiratorial thinking. There are several key things to remember here, the first being that on a personality level, conspiracists tend (not surprisingly) towards distrust or even paranoia, but also towards feeling powerless and cynical. So they tend to think that manipulative people are keeping them down and that there are wheels-within-wheels: Elaborate plots, run by unscrupulous schemers.

Furthermore, the psychological research suggests that conspiracists don't just believe one conspiracy theory. They often believe lots of them. And many of the conspiracies have similar structures — suggesting there are deeply powerful but unseen players working behind the scenes to shape world events.

"A lot of conspiracy theories take as their premise that there’s a small group of people who are plotting to control something, to control the government, the banking system, or the main energy source, and they are doing this to the disadvantage of everybody else," says University of California-Davis historian Kathy Olmsted, author of "Real Enemies: Conspiracy Theories and American Democracy, World War I to 9/11".

There is also usually some initial plausibility to conspiracy theories, says Goldberg — before they go completely off the rails. "There’s this sense of legitimacy to conspiracy theories, I think we all agree that great wealth brings great power," says Goldberg. "But what flips into the conspiracy theories is this sense of malevolence."

And now you can maybe see why oil fits the bill so well:

1. It's the perfect lever for shifting world events. If you were a mad secret society with world-dominating aspirations and lots of power, how would you tweak the world to create cascading outcomes that could topple governments and enrich some at the expense of others? It's hard to see a better lever than the price of oil, given its integral role in the world economy.

"Oil has been the life blood of the world economy for more than a century," says Goldberg, paraphrasing the thinking of a conspiracy theorist. "Those who seek world domination – by fair means or foul – will seek to control supplies and prices in order to disrupt countries; foster recession, depression, run away inflation or deflation; weaken their resistance to takeover."

2. Governments really do depend on oil revenues -- and are deeply involved in oil companies. And then there's the veneer of superficial plausibility. From Russia (which mostly owns Rosneft) to Brazil (which mostly owns Petrobras) to Norway (which mostly owns Statoil) to Saudi Arabia (which owns the gigantic Saudi Aramco), oil and governments are very closely entangled indeed. Any plotting or any conspiracy in this context could, indeed, have world wide consequences. So the conspiracist's belief draws on an existing body of real evidence, before running off into surmise, conjecture, and the highly implausible.

3. Oil producers really do coordinate. And then, there's OPEC, which is widely referred to in the press as a "cartel," and which states up front that its mission is to "coordinate and unify the petroleum policies" of its 12 member countries, which collectively produce 40 percent of global crude, and export 60 percent of it. Again, there's that veneer of plausibility to the idea of some grand oil related strategy -- before the conspiracist goes off the rails. After all, as Michael Levi of the Council on Foreign Relations argued in the Post, OPEC is not actually that coordinated -- that may be its problem.

4. Struggling leaders need somebody to blame. In Putin's case, finally,  we must recognize that a conspiracy theory like the one above is politically expedient -- especially in newly perilous economic times. "Governments use conspiracy theories in order to convince their people to support them," says Goldberg. There's no better way to rally support than to suggest to your people that outside forces — not supply and demand, but malicious schemers — are out to get them.

So in sum, with a surprising and dramatic event like this year's oil price decline, it would be shocking if it did not generate conspiracy theories. Humans believe them all too easily. And they're a lot more colorful than a more technical (and accurate) story about supply and demand.