Another front has opened for geopolitical oil trading - Nigeria, which is again a potential destabilizing force in global oil, alongside Iran. The trigger is dual -- a decision by President Goodluck Jonathan to cancel a highly popular fuel subsidy, which today sent a diverse crowd of thousands of Nigerians into the streets of Lagos, and a murderous slaughter by a militant Islamic group called Boko Haram. The public strike has already halted local trading in the national currency. Now, look for global oil traders to bid up oil prices if they sense a disruption in the export of Nigeria's 2.2 million barrels a day of oil, suggest Bloomberg's Chris Kay and Elisha Bala-Gbogbo.

Trouble in Nigeria is not new -- oil thieves, kidnappers and assorted other gangs have long preyed on Shell, Chevron and ExxonMobil, which have large oil-production operations in the Niger Delta. These fellows get into their boats, attack one of Big Oil's platforms, and before you know it, oil prices have surged around the world. Coming from the Niger Delta himself, Jonathan has credibility that predecessors lacked. Building on initiatives launched by his predecessor, Jonathan has stewarded over comparatively pacific times in the Delta.

But tamping down the Delta has been only one of Jonathan's tasks since becoming president almost two years ago -- he also has sought to reduce corruption, bring some discipline to the overspent state budget, and to build a less volatile economy, all of it toward parlaying Nigeria's immense oil wealth into broadly dispersed prosperity. That was the thinking behind his move Jan. 1 to end fuel subsidies, which he said cost an unaffordable $8 billion a year, mostly benefitting a bunch of middlemen.

Only, gasoline prices have since doubled, infuriating much of the country, illustrating the truism that it is easy to enact a subsidy, but extremely tricky to lift one (Saudi Arabia, too, ought to lift a lavish fuel subsidy, but hesitates to because of this de facto rule of economics, reports the Wall Street Journal's James Herron). Nigeria's lower house of parliament has backed the strikers, and opposed Jonathan on the issue.

In addition to the fuel trouble, Jonathan has declared a state of emergency over a deadly rampage by Boko Haram, which has ordered Christians to leave its northern areas. Some 500 people have died so far in the killing over the last year, including an estimated 43 victims of a Christmas Day bombing at a church in the capital of Abuja. Jonathan has said he suspects that people within his own government and security services secretly back Boko Haram.

Geopolitics have been a primary driver of oil prices since 2006 or so, when the cushion of excess global supply began to become exceedingly thin. Absent the threat of new supply disruptions, prices would probably be considerably lower -- in the $80s-per-barrel range. But there is no sign of a let-up in the Arab Spring, Iran's nuclear ambitions, or in the challenges to Goodluck Jonathan.

Oil whiplash in the Saudi kingdom:  Saudi Arabia, which may or may not have raised oil exports to compensate for the loss of Libyan crude, is now talking internally about increasing spare production capacity to meet an expected surge in oil demand in coming years. That's according to Petroleum Intelligence Weekly, which has been solid on the highly opaque Saudis.

The Wall Street Journal notes this week that confusing information about Saudi production has exacerbated the volatility of the oil market -- the kingdom is by far the world's largest crude exporter, and it cultivates a reputation as a stabilizing force. In February, the Saudis made it known that they were putting more crude on the market in order to compensate for lost Libyan volumes. But this week, Energy Minister Ali Naimi said that in March the kingdom actually lowered production by 800,000 barrels a day for lack of demand. Some traders believe that, before the Saudis made that steep cut, they had been producing about 9 million barrels a day since November for domestic reasons, and simply used Libya as a pretext to make it public.

Whatever the case, PIW reports that the Saudis are now thinking of raising their production capacity to 15 million barrels a day, which would be a 20 percent increase from their current capacity of 12.5 million barrels a day. The discussions revolve around concern about surging Asian demand.

Bidding, not setting: When traders are in the casino, they bid up and down the price of oil -- this week above a smoking $112 a barrel. But are they also counting cards? As soon as you ask such a question, suggesting that trading is a conspiratory sport, you are getting pretty far out there -- manipulation happens (just ask Enron's many victims), but not often enough to be looking over one's shoulder. This week, President Obama fed such suspicious thinking by forming a task force to investigate whether high oil prices are a result of fraud or manipulation. Okay, he is running for re-election. But if you want to reduce some of the spikes up and down in oil prices, charge a higher fee for traders to bet. If it costs more for a seat at the table, betters have more reason to think twice before sitting down.

Anger to the left me, anger to the right: When oil prices shook off the Goldman Sachs malaise this week and went back through a new roof, not only Obama was angered. In Shanghai, truckers went on strike to force down fuel costs and port fees, the Financial Times reported; it was another opportunity for the ultra-paranoid Chinese government to worry about the Arab Spring, and remove any speck of news from the Internet.  Meanwhile, Russia's Transneft is on the warpath against China over the price of oil. Transneft wants world prices for the crude it's shipping to China through Skorovodino, in Siberia, but somehow the two sides have a different idea of what that world price is, reports John Helmer on his blog. Prices are not going down soon, as we see in the worsening trouble reflected by Syria, and the world is only becoming more complicated, as I discussed with Scott Tong this week on Marketplace. And it's not even summer yet.

Good or bad luck in Nigeria? There is peace in the Niger Delta, but fury in the north as Nigeria -- the source of some 10 percent of the United States' crude oil supply -- prepares for its next round of voting, this time for local offices. So will we have debilitating trouble in another important oil state? Much depends on the actions of President Goodluck Jonathan, who won the right to continue for a full term in office after taking power on the death of his predecessor. Jonathan is from the south, which is generally what infuriated the north and supporters of his opponent. Writing in the New York Times, Dele Olojede, who edits the Nigerian newspaper NEXT, observes worrying signs in the unprecedented violence and disrespect of hallowed officials present in the north. Olojede calls for statesmanship by Jonathan and former military ruler Muhammadu Buhari, whom he defeated in the election.