You probably gripped your stomach -- and your wallet -- last year when crude prices ran to nearly $150 in July, then turned and plummeted into the $30s before 2008 ended.

There were lots of reasons offered for this wild ride, with simple supply and demand and speculators' antics leading the pack. But a wild ride it was, so wild that most of us haven't noticed that crude has essentially doubled from the low. So why, with oil demand still falling among the developed nations, have prices moved higher?

Again, there are lots of reasons, including concerns that the rapid price decline has knocked out scores of oil and gas projects, such that when the economy recovers and demand returns, our supplies will be insufficient. That's a valid concern, but there's another hypothesis that's receiving almost no attention -- one that could push crude lots higher.

If you think about it, several of the producing nations are virtual tinderboxes, and it wouldn't take much to ignite a geopolitical explosion that would send crude prices to goodness knows where. Indeed, just the past two weeks have seen a bevy of threats and outright violence, much of which has generally been ignored.

Nigeria's not on the MEND
Take Nigeria, for instance. Most of the nation's oil comes from the Niger Delta, where local tribes have felt left out of the spoils of energy. They therefore, under the title of the Movement for the Emancipation of the Niger Delta, (MEND), have launched a series of attacks against Western oil companies and their employees in recent years.

In January, for instance, an armed group attacked an ExxonMobil (NYSE:XOM) platform, which was operating a couple of hours off the Nigerian coast. And then last week, MEND warned companies working in Nigeria -- which would include Royal Dutch Shell (NYSE:RDS-A) and Chevron (NYSE:CVX), among a host of others -- to evacuate their personnel.

Then, true to its word, MEND launched a series of attacks against Nigerian military patrols, patrol boats, petroleum infrastructure, and employees working on them. While the details of the attacks and their aftermath remain foggy, it appears that skirmishes continued into the weekend. A string of similar events have chopped Nigeria's crude production by nearly 25% since 2006.

Hugo's at it again.
And then there's our friend Hugo Chavez, who's again misbehaving in Venezuela. Just 10 days ago, Chavez helped himself to the assets of Williams Co. (NYSE:WMB), a Tulsa-based company that, among other things, operates high pressure gas injection plants. Those antics followed an event earlier in the year when Venezuelans forcibly took over operation of an Ensco (NYSE:ESV) rig, after the company refused to continue its operations due to non-payment.

Shortly after crude prices began to fall late last summer, and following his decision three years ago to nationalize energy -- and numerous other industries -- Chavez stopped paying most service firms, although word has it that the biggest members of the sector, Schlumberger (NYSE:SLB) and Halliburton (NYSE:HAL), for instance, have been relatively unaffected. Nevertheless, at the end of last year, Petroleos de Venezuela (PdVSA), the government's oil company, owed its suppliers nearly $14 billion.

The new law, passed less than two weeks ago, will permit PdVSA to use government debt instruments to pay the firms. Regardless of the form of the payments, however, as in Nigeria, the chaos in Venezuela has led to a significant production cut in the nation.

And potentially the big one ...
Finally, there remains the possibility of Iranian energy disruptions that could be far more devastating than anything emanating from Nigeria or Venezuela. Some think there is a growing possibility of an Israeli attack on Iran. Indeed, former Vice President Cheney was interviewed last week on CNBC, where he made this prediction: "The Israelis look at developments in Iran, and they have stated publicly that they believe a nuclear-armed Iran is something that fundamentally threatens their existence. So, I would expect them to try to do something about it."

All this occurs following an announcement last summer by Iran that it has developed a naval weapon capable of destroying any vessel within a 300-kilometer radius. As such, the nation claims it could close the Strait of Hormuz -- through which 40% of all seaborne oil passes -- "easily and on an unlimited basis." Such an event would clearly blast crude prices through the stratosphere.

So while crude seems to be settling around $60 a barrel, I'm convinced that the specter of world events will likely push it at least somewhat higher. On that basis alone, I'd urge my Foolish friends to include energy representation in their portfolios. My own favorite continues to be the biggest of them all, ExxonMobil.

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Fool contributor David Lee Smith doesn't own shares in any of the companies mentioned above. He does welcome your questions or comments. The Motley Fool has a well-fortified disclosure policy.