Oil and what it represents - energy - have always been a source of conflict.
By Paul Reynolds
BBC News Online world affairs correspondent
The Japanese attack on Pearl Harbor had its origins, at least in part, in a decision by the United States to limit oil exports to Japan in 1941 in response to the Japanese invasion of China.
Oil was a factor in Japan's surprise 1941 attack on Pearl Harbor
Japan was almost totally reliant on imported oil, mainly from the United States, and it needed oil for its navy.
It concluded that if the American tap was going to be turned off, it would have to get its oil elsewhere. This was a factor in its decision to invade the oil-rich Dutch-held Indonesian islands.
Coups and power-play
Japan still relies on imported oil but this now comes substantially from the Middle East, another part of the world where oil has long played a vital role.
Britain first became interested in the Gulf because of its maritime interests, long before oil was discovered.
Kuwaiti wells on fire in 1991 after the Iraqi invasion
Then, when oil extraction was developed in the 1930s, the strategic value of the region increased significantly.
Other powers began to get interested, especially the United States. The West was determined to secure the Gulf as a main source of its energy.
Oil played its part in a 1953 coup in Iran - organised by the US and Britain. They managed to overthrow an elected prime minister, Mohammed Mossadegh, and installed Shah Reza Pahlavi whose reign came to an inglorious end at the hands of Islamic fundamentalists in 1979.
Mossadegh's main sin was to have nationalised the British-owned Anglo Iranian oil company.
Just how far the United States was prepared to go for oil was shown by the recent release of documents from the British National Archives.
An intelligence assessment by the British government in January revealed that in 1973 Washington drew up a plan to seize oilfields in Saudi Arabia, Kuwait and Abu Dhabi to counter an Arab oil embargo against the West.
One recent study paper by an American military analyst even suggests that one day the United States and Europe might be in conflict over dwindling Middle East oil supplies.
The analyst, Major Chris Jeffries, Assistant Professor at the US Air Force Academy wrote: "Is it unthinkable that the US might enter into an agreement with the Middle East to secure its supply over the interests of the other industrialized nations - including Europe?"
The intervention by the United States and its allies over Kuwait in 1991 was in large part motivated by a need to secure oil and also to prevent Saddam Hussein from expanding his access to it.
And, although the more recent war with Iraq had other motives as well, oil was a factor as the US Vice President Dick Cheney, warning of Iraq's ambitions, said in August 2002: "Saddam Hussein could then be expected to seek domination of the entire Middle East [and] take control of a great proportion of the world's energy supplies..."
But oil does not just produce outside intervention. It can produce internal abuse of power.
Will Baku see another oil boom?
Saddam Hussein himself is a prime example: it was oil that gave him the resources with which to arm himself.
Looking ahead, new areas of interest are opening up, especially the Caspian Sea where a new "Great Game" is developing to mirror the rivalry between Russia and Great Britain in Asia in the 19th Century.
One of the countries at the heart of Caspian Sea development is Azerbaijan and it is instructive perhaps to recall that its capital, Baku, was once the capital of the world's oil exports.
That was back in the early 20th Century. Baku became an international city, with grand villas built by locals who had got rich and foreigners who came to get rich. The city even put up an ornate opera house to mark its prestige.
The new black gold
Baku's oil was a target for the German army in World War I and the city was briefly occupied by a British contingent. It was then taken by the Soviets, equally keen on getting at the black gold.
Hitler aimed for it again in World War I