62 years ago last week, in 1941, the Imperial Empire of Japan launched one of the most deadly strikes in U.S. history. By the end of the day, the U.S. Navy’s Pacific Fleet was nearly crippled—and 2,335 American servicemembers were dead.
Yet, while the impact of the attack on Pearl Harbor still ripples through our society today, the real impetus for the Japanese attack isn’t well known. Pearl Harbor was attacked because of Japan’s need for an essential resource—one that the U.S. still fights over today: oil.
The motivations behind the Japanese attack on Pearl Harbor were best framed by Japanese Prime Minister Hideki Tojo, who said a month prior to the attack, “Two years from now we will have no petroleum for military use. Ships will stop moving…I fear that we would become a third-class nation after two or three years if we just sat tight.” In other words, Japan understood its future hinged on fuel.
In 1940, Japan imported more than 90% of its oil requirements, including 80% from the United States. President Roosevelt sought to use this dependence as a “noose around Japan’s neck”. In an attempt at coercive diplomacy, he instituted an embargo on shipping essential supplies, including oil, to Japan.
After stunning the U.S. Navy at Pearl Harbor, the Japanese were able to capture the oil-rich Dutch East Indies and restarted production at its wells. In the two years that followed, the Japanese were able to fuel their fleet and won a series of victories.
But when U.S. submarines started targeting Japanese oil tankers, cutting off the crucial shipping lines between the Southern Zone and the Home Islands, Japan’s vulnerabilities became obvious. Japan’s fuel shortages began dictating strategic decisions and opening opportunities that allowed the U.S. to turn the war in the Pacific in its favor.
Pushed to the brink, Japan became desperate for fuel to power its ships and aircraft. It expended enormous resources trying to create synthetic fuels out of coal, which failed to pay off. Ships and vehicles were converted back from oil to coal, sapping military capability and range. At its most dire, Japan began a nationwide campaign to compel its citizens to dig up and cook pine roots from all over the countryside to create a crude oil substitute, leaving barren stretches of land.
None of it worked. The pine root fuel ended up damaging aircraft engines. Planes and ships laid unused because they had no way to power themselves. And forced to conserve fuel, warships with any fuel arrived at crucial battles too late to provide support. In fact, when General Douglas MacArthur landed in Japan to sign the agreement for Japan’s surrender, the only vehicles the hosts could provide were powered by charcoal. The vehicle carrying MacArthur repeatedly broke down on the ceremony.
America’s experience in the Pacific Theater during World War II underscores petroleum’s role as a strategic commodity. The fate of militaries—and nations themselves—relies on assured access to adequate supplies of oil.
It’s a lesson that’s even more important today for the United States, as our military is incredibly dependent on access to petroleum-based fuels.
This past decade of war—in Iraq and Afghanistan—was waged largely by the least energy-intensive branches of our military: the Army and Marine Corps. But as the war winds down, the Pentagon is shifting its focus (and therefore, the fuel burden) to our most fuel-intensive branches: the Navy and Air Force.
The military is doing so by refocusing its forces to the Pacific Rim. With an area of responsibility that covers more than half the earth’s surface, America’s Pacific-based forces burn up enormous amounts of fuel. The rebalance to Asia will mean that the U.S. military—already the largest institutional consumer of fuel in the world—will require even greater energy resources to accomplish its strategic goals.
In light of these developments, the lessons of Japan resonate today. The U.S. military must maintain the “freedom of action”—the ability to go where needed and act decisively—to accomplish its missions and project power amid new threats. That means that we must treat access to energy as an objective, not an assumption. We need a more capable, agile and sustainable force, and it’s more important than ever to consider energy requirements in strategic planning and platform acquisition.
That’s why a “defense energy” community is taking shape, consisting of Department of Defense and service branch officials; technology companies; academics; and energy entrepreneurs. It is helping to develop and implement technologies that increase the energy productivity of our forces. Events like the Defense Energy Summit are bringing together stakeholders from around the country.
Fortunately, our military is already taking action. The Navy is investing in hybrid-drive propulsion systems. The Air Force is installing advanced turbines on its aircraft to increase range and stay in the air longer. And the U.S. Department of Defense is entering into agreements with Pacific Rim allies—like Australia—to develop advanced fuels for military use. These fuels work perfectly with existing equipment. And since they’re made from sources like algae and recycled waste oils, don’t compete with food production.
Incorporating emerging clean energy technologies—and diversifying energy sources that power our ships and aircraft—will be essential for our military to accomplish its strategic goals. Now, in particular, it is imperative that we reflect on our history in the Pacific, and ensure that we learn from our experiences at war with Japan.
Michael Wu is the Advocacy Policy Director at the Truman National Security Project and the Center for National Policy, a Washington, DC-based policy organization. He also helps leadOperation Free, a nationwide coalition of veterans and national security experts that advocate for securing America with clean energy. Views expressed are his own.