We in the U.S. tend to consider Iran to be the world's biggest threat to maintaining a lid on crude prices. That's a geopolitical, rather than a supply-and-demand, conclusion: The country's crude exports essentially don't register meaningfully in the U.S., but a fear of a conflagration involving the perpetual rogue of a nation clearly is built into today's global oil prices.

As you know, Iranian representatives met last weekend in Istanbul with their counterparts from the world's major countries, specifically the five members of the UN Security Council plus Germany. Some are comforted by the lack of incident during the 10-hour session and a decision to hold another confab on May 23. I'm not among them.

Was anything accomplished?
The ultimate objective is to prod the Persians into jettisoning their rapidly progressing development of nuclear weaponry, but as The Wall Street Journal noted Monday, "American and European officials acknowledged Saturday they didn't press Iran during the Istanbul meetings to take any specific actions to curb its nuclear program." I therefore can't help but concur with the notion propounded by Israel's Prime Minister Benjamin Netanyahu that Iran "has got five weeks to continue enrichment without any limitation and inhibition."

At the same time, however, we'd be foolhardy to ignore either the elements of progress or newly emerging risks in Nigeria, Africa's most populous country and the fifth-largest supplier of crude to the U.S. Beyond those credentials, Nigerian crude is of the valued -- but progressively rarer -- light, sweet variety that is far more susceptible to refining than the "heavy" oil we obtain from Canada, Venezuela, and, more frequently of late, Saudi Arabia.

Since the ascendancy to the Nigerian presidency nearly two years ago of the wonderfully named Goodluck Jonathan, there has been clear progress in the country and increased optimism about its development from my friends in the energy industry. However, the country is now beset by two pesky groups, rather than one.

But on the positive side, last May the country signed domestic natural-gas power supply agreements with several major international companies, including Chevron (NYSE: CVX) and Italy's Eni (NYSE: E). At the same time, the government has been laboring -- seemingly interminably -- on a petroleum industry bill that is being designed primarily to improve the efficiency of Nigeria's state-run oil company, the Nigerian National Petroleum Corporation.

On the MEND again
At the same time, two dangerous -- but very different -- dissident groups pose perpetual threats, both to the country as a whole and ultimately to the group of major oil companies attempting to operate there. You no doubt recall the infamous Movement for the Emancipation of the Niger Delta, or MEND, which is comprised of tribesmen from the Niger Delta area who generally have been excluded from holding lucrative energy-related jobs in favor of those belonging to the nation's more powerful inland tribes.

MEND's "remedy" has been to launch periodic attacks on the operations of the companies operating both in the Delta and offshore. Among the group's incursions of significance was a November 2010 attack on ExxonMobil's (NYSE: XOM) Oso platform in the Delta. In that sortie, eight Nigerian crew members were kidnapped, and the company's production was reduced for a time. For its part, Royal Dutch Shell (NYSE: RDS-B) has reduced its asset base in the country in response to attacks by the militants.

And while it had appeared that MEND had become somewhat more docile since Jonathan assumed office, as recently as last week it issued threats of more attacks on pipelines and other facilities remotely related to the Nigerian oil industry. In making its announcement, MEND claimed to have recently attacked a Total (NYSE: TOT) facility in Bayelsa State. So what had been hoped to be a movement toward tranquility may only have been the calm between storms that is typical of terrorist organizations.

Boko Haram adds to the fray
As if that didn't create enough chaos, Nigeria is also being rocked by the violence of a group named Boko Haram. Divide the country in half laterally, and you'll discover the northern portion to be largely Muslim, while the South is essentially Christian. Boko Haram is an Islamist organization that has saved much of its venom for Christian holidays. On Easter Sunday it detonated a pair of deadly explosives. One, a car bomb across from the All Nations Christian Assembly Church in the city of Kaduna, killed dozens, while a second blast in nearby Jos killed 16.

The Easter bombings followed the killing of 44 in a Christmas Day bombing. And on Jan. 20, explosions assumed to be the work of Boko Haram killed another 186 in the city of Kano. Kaduna also recorded more than 800 killed on the country's last election day as Islamists seethed about the election of Jonathan, a Christian.

While I don't speak the language, I'm told that Boko Haram means "Western Learning is Sinful" in Hausa, which is spoken in the North. It appears that the group's anger has been precipitated by the disparity between the abject poverty of Nigeria's North and the higher, energy-related standard of living in the South. Unfortunately, these tragedies are occurring as the Jonathan government is attempting to foster an image for Nigeria as the leader of the African nations and the appropriate starting point for investment in the poverty-stricken continent.

The threat from Boko Haram, which seeks to impose Sharia law across Nigeria, is hardly shrinking. As recently as Wednesday, with intel indicating the possibility of attacks in the Nigerian capital of Abuja, the U.S. government issued stiff warnings to citizens in the area.

Foolish bottom line
It's difficult to know where this intensifying -- but underreported -- situation is headed, just as Iran's next steps remain cloudy. The only certainty is that, unless these tinderboxes are controlled, they'll likely continue to exert upward pressure on crude prices. Foolish investors would be wise to watch the situation closely -- perhaps starting by clicking on the links below and adding the above-named companies to their individual watchlists.