Concerns about corruption are even more pronounced in Nigeria and Angola.

Oil-rich Angola is taking in two and a half times the cash it did three years ago. Hotels in the capital, Luanda, are booked months in advance, largely by foreign oil companies. Sales of luxury cars are booming, and the International Monetary Fund projects the economy will grow 24 percent this year, one of the world’s fastest rates. Yet analysts for the Catholic University of Angola’s research center say two in three Angolans live on $2 or less a day, the same ratio as in 2002, when the country’s decades-long civil war ended.

The government is eager to show that oil wealth is benefiting ordinary citizens. It has rebuilt 2,400 miles of roads, refurbished 4 airports, and laid 430 miles of new railroad track.

But many Angolans take it as a given that oil has enriched public officials most of all. In 2003, a newspaper in Luanda identified the 20 richest people in Angola: 12 were government officials; 5 were former officials. Angola’s growing muscle — it is now the biggest oil supplier to China and the sixth biggest to the United States — is leading it to rethink its global position. It recently joined the Organization of the Petroleum Exporting Countries and is limiting its cooperation with the I.M.F.

In perhaps the most far-reaching change, China has become Angola’s financier, lending Luanda as much as $12 billion for the country’s reconstruction, in return for guaranteed oil supplies.

The contest among importers to secure access to oil supplies has become fierce.

China, a one-time oil exporter that now must import half its oil to lubricate its booming economy, is facing politically troublesome shortages of fuel from Shenzhen to Beijing, as Chinese refining companies refuse to supply diesel at unprofitable state-regulated prices. To head off a crisis, China raised retail prices for fuel nearly 10 percent on Nov. 1.

India is potentially even more vulnerable than China, some analysts say. Although it consumes a third as much oil as China, it imports 70 percent of its oil. It also has no strategic reserves, and demand is growing faster than in any other economy except China’s. Like China, India subsidizes fuel, particularly the kerosene used by lower- and middle-class families for cooking — a policy that costs it some $12 billion a year. If oil reaches $100 a barrel and stays there, analysts say, India will be forced to roll back those subsidies.

“Sooner or later, prices are going to bite,” said Subir Gokarn, Standard & Poor’s chief economist in Asia. “Clearly household budgets will be significantly affected.”