Seventy years ago last Saturday, 91,000 exhausted, frozen and starved German and Romanian soldiers surrendered to the Soviet forces at Stalingrad. About 1 million people had been killed on each side during the six-month battle. Stalingrad marked the beginning of the end for Adolf Hitler's attempt to conquer the USSR. It also demonstrated the futility of modern "resource wars".
With the past decade's high commodity prices and fears of shortages of energy, minerals, food and water, commentators have portrayed numerous political and military acts as caused by greed for resources.
Hitler's motives for attacking the USSR were various: the threat it posed to his control of Europe, ideological hostility to communism, his racial contempt for Slavs, the desire to win "living space" for German settlers. But the urge for materials to feed his war machine - Ukrainian wheat and coal and Caspian oil and metals - was a major factor.
After advancing deep into the Soviet Union in 1941 but failing to capture Moscow, the Axis "Case Blue" offensive of summer 1942 intended to capture the oil of Baku, in modern Azerbaijan. Dogged by fuel shortages, the Germans were unable to cross the Caucasus Mountains, and diverted to their fruitless and militarily pointless attempt to capture Stalingrad. From this point, the downfall of the monstrous Nazi empire was inevitable.
The Pacific theatre followed a similar pattern. After a US petroleum embargo, the Japanese attacked Pearl Harbor and conquered Indonesia to secure its oil. But their supply lines were cut by American submarines: by the war's end, some of their road vehicles had to run on gas made from wood.
Several modern wars were launched at least partly over resources: the 1932-35 Chaco war between Bolivia and Paraguay, Saddam Hussein's attempt to seize the oil-rich Khuzestan province in the 1980-88 Iran-Iraq conflict, and his attack on Kuwait in 1990.
No oil has been found in the coveted territory Paraguay captured from the Bolivians. The Iran-Iraq war cost Iraq some US$195 billion (Dh716.23bn), caused immense destruction and loss of life, and did not capture any oil - indeed, Iraq's own production was badly disrupted.
The importance of Iraq's oil in motivating the 2003 US-led invasion is still unclear. After it, 150,000 occupation troops were unable to keep order in a mid-size country, and production did not recover to pre-war levels for eight years.
Even if the US had somehow stolen Iraq's entire oil output, it would not even pay the interest on the war's estimated $3 trillion cost. And in reality, with the planned withdrawal of ExxonMobil, no US oil company is operating in the country outside the autonomous Kurdish region.
Now the French intervention in support of Mali's government is being described by some as a resource grab - although Mali has no oil, but may have uranium. Supposedly the French aim to secure next-door Niger's uranium - instead of the easier expedient, one would have thought, of simply deploying a defensive force in Niger itself.
These episodes teach us that modern "resource wars", if they exist, are catastrophically expensive and unsuccessful. Modern warfare is too costly; resources are not valuable enough. They are too vulnerable to insurgency and interdiction.
Today is not the autarkic world of the 1930s and 1940s, but one in which most resources are traded in markets and available to the highest bidder. The vast bulk of the profits go to the host country, not to a colonial government or monopolistic corporation.
We should avoid simplistic explanations that pin a single cause on wars. Energy security can be a reasonable motivation for proportionate military action; resource-grabbing is not.
Indeed, even the deluded dictator Hitler was not impelled solely by his lust for Soviet oil as he urged his troops to stand their ground at Stalingrad.
Robin Mills is the head of consulting at Manaar Energy, and author of The Myth of the Oil Crisis and Capturing Carbon