Here's What You Need To Remember: Even success on the battlefield does not necessarily mean a successful policy.

For the last hundred years, oil has been a frequent reason for war. Nations have fought wars, or shaped their military strategy during a war, to conquer oil fields or prevent rivals from controlling the commodity that is the lifeblood of industrial economies and modern militaries.

But what good is capturing an oil field when you wreck your country in the process? Several nations have learned the hard way that the price for capturing oil can be much greater than its value.

Consider the outcome of these oil wars.

The Pacific War

Japan's decision to go to war with America in December 1941 had many causes, from Japanese militarism, to disputes over control of a weak China, to the ultimate question of who would be the dominant Pacific power. But the immediate catalyst was the August 1941 U.S. and European embargo on oil, spurred by Japan's war in China as well as its occupation of French Indochina. Japan lacked domestic oil production, but it did have an industrial economy and a large, powerful navy and air force that needed petroleum.

Japanese leaders felt trapped between two choices: back down in the face of the embargo and forego their imperial ambitions, or take advantage of Hitler's conquest of Western Europe to seize the oil fields in the Dutch East Indies and British Southeast Asia (which the Europeans had taken from the natives in the first place). However, while the Europeans were too weak to defend their possessions, the United States had a powerful Pacific fleet that could intervene unless neutralized.

Destroying the U.S. Pacific Fleet at Pearl Harbor did not solve Japan's oil problem. Capturing the Asian oil fields was easy, but shipping the oil back to Japan was not. By 1945, the U.S. submarine blockade, as well as aerial mining of Japanese waters, had so decimated Japan's tanker fleet that the Japanese cut down forests to make crude aviation fuel. Attacking America was supposed to guarantee Japan unlimited oil, but instead it led to the destruction of the empire.

Stalingrad

If any leader was obsessed with oil, it was Hitler, who complained that "my generals know nothing about the economic aspects of war." But unlike their Führer, they would have known better than to send their panzers off on a mad dash to capture oil.

The German attempt to defeat the Soviet Union in a single blitzkrieg campaign had failed in the summer of 1941. By June 1942, the depleted German armies were only strong enough to mount an offensive in just one sector of the vast Russian front. Hitler concentrated his best divisions in south Russia, to drive on the rich oilfields of the Caucasus. Though Operation Blue started well and almost reached Stalingrad by August, the Germans soon faced a dilemma: mass their forces and turn south to capture the oil, or continue driving west to capture Stalingrad as a bulwark against Soviet forces assembling in the interior of Russia.

Hitler characteristically tried to have it all. The German armies split, with one prong advancing toward the Caucasus, and the other driving toward Stalingrad. Both prongs came close to success, but neither had sufficient troops or supplies to accomplish their mission. The Nazis could not capture the oil centers of Grozny and Baku, though they could boast of planting their flag on Mount Elbrus, the highest mountain in the Caucasus. Meanwhile, to the north, the Soviets quietly massed their forces for a counterblow at Stalingrad. Within six months, the German Caucasus expedition was in full retreat, while more than 100,000 Germans surrendered at Stalingrad, marking a turning point in World War II. Dreams of oil ended with Hitler's Iron Dream shattered.

The Iran-Iraq Tanker War

The Iran-Iraq War of 1980-88 dragged on for eight bloody years, and dragged down both of the combatants. Frustrated by the stalemate on the ground, both sides sought to strike at their enemy through oil. Iraq began the Tanker War in 1984 by attacking Iranian oil facilities and vessels trading with Iran. Iran struck back with air and naval attacks against Iraqi ships and oil sites and, more importantly, laid naval mines in the Persian Gulf. Despite attacks on some 450 ships, neither side was able to devastate the other or to compel surrender. But the Tanker War did have one major outcome: it led the United States into direct hostilities with Iran after American warships began escorting Persian Gulf merchant traffic. After Iranian mines and missiles damaged civilian traffic and an American destroyer, U.S. warships, aircraft and SEAL commandos destroyed Iranian ships and naval facilities.

Saddam Hussein's Invasion of Kuwait

In 1991, Iraq invaded neighboring Kuwait over disputes about Iraqi war debts, Kuwaiti oil overproduction, Iraqi claims that Kuwait was rightfully a part of Iraq and probably a desire to seize Kuwait's oil reserves. The Iraqi Army had little trouble disposing of its little neighbor, but the invasion quickly put it at loggerheads with the United States, which had actually supported Iraq during the Iran-Iraq War. Despite a UN ultimatum to withdraw from Kuwait, Saddam Hussein refused to budge. The result was 500,000 U.S. troops in Saudi Arabia, the American-led blitzkrieg of Desert Storm and the devastation of Iraqi military power. Iraq had previously been one of the major powers in the Arab world; Saddam Hussein's quest for oil left it broken and isolated.

The U.S. Wars in Iraq

Whether—or rather, to what degree—the U.S. wars with Iraq in 1991 and 2003 were motivated by oil will debated for years. Yet even to what extent there were other reasons for massive military intervention in the Persian Gulf, it is hard to believe that America would have dispatched a half-million troops if Nigeria had invaded Cameroon. The presence of American troops in Saudi Arabia helped spur the rise of Osama bin Laden, Al Qaeda and ultimately 9/11. The full cost of the U.S. invasion of Iraq in 2003 will be paid for by American taxpayers for decades.

For the American leaders, and plenty of others throughout history, the price of oil indeed proved to be higher than any could imagine.

Michael Peck is a contributing writer for the National Interest. He can be found on Twitter and Facebook.This article is being republished due to reader interest.

Image: Wikimedia Commons/Public domain

Image: An Iraqi flag is seen on a military vehicle at an oil field in Dibis area on the outskirts of Kirkuk, Iraq October 17, 2017. REUTERS/Alaa Al-Marjani