For almost a decade, oil-rich countries have watched the power of their national energy companies increase as oil prices rose from $10 a barrel to a peak of almost $150.
As international oil companies were failing to find new big fields, the shift in power between national and international oil companies became so stark that ExxonMobil of the US was the only international oil company to make the FT's 2007 list of the world's seven most important oil companies. The rest, led by Saudi Aramco, were national oil companies.
But many national oil companies face political and technical challenges so great that they are failing to exploit their countries' vast potential. The recent collapse in oil prices means countries struggling to increase their production will be left having to accept far lower revenues.
And as oil prices fall and companies such as Rosneft, Russia's national oil company, and Gazprom, its gas monopoly, struggle under the effects of the credit crunch, the task of boosting production will become even more difficult. This has led oil executives and even the Opec oil cartel to warn that the world may well find there is again not enough supply to meet demand once it recovers from the downturn.
The issue of declining oil fields is of key importance. In fact, the International Energy Agency, in a draft of its flagship World Energy Outlook, to be published next month, says: "The future rate of decline in output from producing oilfields as they mature is the single most important determinant of the amount of new capacity that will need to be built globally to meet demand."
Some national oil companies, such as Saudi Aramco, are well-equipped to rise to the challenge. But others, including the national oil companies of Kuwait and Mexico, are not. But the governments of Mexico, Kuwait and other oil-rich nations have proven unwilling or unable to entice international oil companies to help them. Even in Mexico politicians last week failed to pass radical enough reforms to lure big international oil companies.
One of the problems is the historical legacy of international oil companies, whose predecessors treated oil-rich countries like serfs of their empire.
Even in countries, such as Libya, which has embraced international oil companies despite a strained history, the economic terms have been far less generous.
Another issue sapping international oil companies' power is that the developed world, from where they hail, is quickly losing its importance as a customer.
Preliminary data from a draft of the latest IEA report underlines that point: all the increase in oil demand until 2030 comes from emerging countries.
This is the clearest indication yet that the focus of the industry on the demand side is moving towards emerging nations such as China. PetroChina, until the recent rout in share prices, was the world's biggest oil company by market capitalisation.
Gazprom, Sinopec and Petrobras also made the top 10 of PFC Energy's 2007 list of the world's biggest energy companies by market capitalisation.
The implication of this is clear: national oil companies will decide whether the world will have enough oil in the next decades to allow China and other developing nations to pull themselves out of poverty and rich nations to maintain their high standard of living.
