An F-18 fighter jet sat bathed in soft, showroom lighting behind President Obama as he proposed opening large swaths of American coastlines to oil and gas drilling in a major energy policy speech two years ago.

Promising a centrist approach to energy with an emphasis on clean power, Obama turned to the aircraft dubbed the "Green Hornet" because it was certified to run on a 50-50 biofuel blend.

"The Pentagon isn't seeking these alternative fuels just to protect our environment. They're pursuing these homegrown energy sources to protect our national security," Obama said. "Our military leaders recognize the security imperative of increasing the use of alternative fuels, decreasing energy use, reducing our reliance on imported oil, making ourselves more energy-efficient."

Obama has invoked the Pentagon's energy efforts frequently, especially as election politics have ramped up in recent months. In his State of the Union speech in January, the president announced the Defense Department would purchase a gigawatt of clean energy in the coming years. When he swung through the West a week later to promote his energy agenda, Obama made a well-photographed appearance at Buckley Air Force Base in Colorado.

And at each stop, one man has been at Obama's side: Navy Secretary Ray Mabus, the Pentagon's zealous energy crusader.

An ardent reformer and politically wired Democrat who has been governor of Mississippi, ambassador to Saudi Arabia and head of the Obama administration's Gulf Coast restoration plan following the 2010 Deepwater Horizon oil spill, Mabus has a deep Southern drawl, a camera-ready smile and a knack for capturing media attention.

But most of all, he believes in the bold stroke.

"He is not a disciple of the status quo," said former Mississippi Gov. William Winter (D), whose administration Mabus served in during the early 1980s. "He rocks a lot of boats."

Mabus, 63, faced big challenges when he became Navy secretary -- a job also held by retired Virginia Republican Sen. John Warner and current Virginia Democratic Sen. Jim Webb before their congressional careers.

When he arrived at the Pentagon in the spring of 2009, the Navy's shipbuilding program was in shambles, admirals were struggling for a vision of the future force in the midst of two entrenched ground wars that had left the Navy mostly on the sidelines, and the U.S. economic troubles cast a long shadow that promised to shroud even the Defense Department.

But during briefings to get him up to speed on the sprawling Navy complex ahead of his confirmation hearings, Mabus' ear perked to something unexpected -- energy.

"It would keep coming up in different briefings, in terms of the budget and how the price of fuel was going up pretty dramatically, in terms of when the [USS] Cole was attacked [in Yemen in October 2000] -- it was attacked when it was refueling -- and the sort of military vulnerability that energy was," Mabus said in an interview with Greenwire. "It was really stark."

Within five months, Mabus would declare as one of his signature priorities transforming the way the Navy uses energy and lay out goals that even the most optimistic renewable energy advocates admit are a stretch.

"We go where we are needed, and we decisively accomplish our mission, whatever that might be," he told military brass and top DOD civilians that fall. "We must be no less bold in our thinking when it comes to energy reform, no less willing to embrace risk."

For a full two years, it looked as though Mabus had cracked the code of energy policy, translating concerns about energy security into a proposal that both conservatives and liberals could support. Environmentalists were thrilled with the image of a green military and understood the potential its purchasing power had to spark large-scale change in the rest of the country. Conservative hawks, meanwhile, knew that insurgents were targeting fuel supply lines and saw how solar equipment made Marines in Afghanistan more agile.

The Navy secretary took every opportunity to tout his program, speaking at energy conferences around the country and steering press interviews to the topic.

But then he crossed the line with Republicans.

Last summer, at the direction of the president, Mabus announced plans to use a little-known defense procurement law to invest $510 million in funds from the departments of Navy, Agriculture and Energy in building commercial-scale biofuel refineries.

In budget season, the Navy effort collided with the GOP's two main talking points: that Obama's clean energy program was picking politically connected favorites for taxpayer dollars and that looming defense cuts stand to decimate the world's most powerful military.

"You're not the secretary of the energy, you're the secretary of the Navy," the normally even-tempered Rep. Randy Forbes (R-Va.), who leads the House subpanel with jurisdiction over military energy and environment issues, snapped at Mabus during a February budget hearing.

Now, the Navy's energy program has been pulled into the bare-knuckles brawl over national energy policy. The House included a provision reining in key aspects of the biofuels effort in the defense authorization bill it passed in May, and a floor fight is shaping up in the Senate after similar language made its way into that chamber's bill.

Although the issue only truly hit Washington's radar this spring, for Mabus it has been decades in the making. And for a man with a history of pushing controversial, sweeping efforts for reform -- some gloriously successful, others skewered by political miscalculation -- it promises to be his highest-stakes battle yet.

'Mississippi will never be last again'

Running for governor of Mississippi in 1987, 39-year-old Mabus left little room for confusion about his intentions. He promised voters "basic, drastic change" for the state that was at the time ranked last in the nation for nearly every indicator of success, from per capita income to literacy.

On the campaign trail, he vowed in Scarlett O'Hara fashion, "Mississippi will never be last again."

Few places were more resistant to change than the Mississippi where Mabus grew up.

His youth was set against the backdrop of the nation's most divisive segregation battles. The only child of a central Mississippi hill country timber farmer, he arrived at Ole Miss for college just four years after the town had erupted in riots when the school admitted its first black student -- an incident that ended when hundreds of U.S. marshals were called in to quell the chaos.

But when Mabus appeared on the state's political scene in the early 1980s, Mississippi had reached an inflection point with the fiery fights over segregation finally simmering down and pocketbook issues rising to the fore. And in less than a decade, he positioned himself as the state's star reformer aiming to build a new Mississippi.

It began when Mabus joined the Winter administration, becoming part of a team of young aides working on education reform.

The aides, whom opponents mocked as the "boys of spring," assembled a package of reforms but quickly ran into a brick wall at the state Legislature, where fiscal conservatives refused to raise taxes to fund the program.

After failing to get the education package through the Legislature in the first session, the "boys" thought they had finally scrounged enough votes to pass it on the last day possible in the 1982 session, only to be shocked when the speaker adjourned the House early and killed the bill.

Winter said it was a hard blow, but he accepted the failure. His aides, however, did not. Instead, they took the issue to the public and rallied enough support to pressure the Legislature into calling a special session where the bill passed overwhelmingly.

The coup served as a launching pad for Mabus, who then ran for state auditor and won in 1984. The young politician tapped the full stretches of the post's authority -- and its ability to draw the media spotlight -- challenging some of the most powerful public officials with his audits. He won back $1.7 million for the state and sparked an FBI investigation that led to more than 40 indictments.

'This is a hard, hard climate down here'

In January 1988, Mabus swept into the Mississippi governor's mansion on a wave of optimism. But he quickly learned it's easier to promise change than to deliver it.

One of Gov. Mabus' primary aims was to extend the education reforms begun in Winter's administration. He swiftly passed a pay raise for teachers, but his broader plan again became hamstrung in the Legislature when lawmakers approved the program but refused to sign off on the state lottery Mabus wanted to use to finance it.

It was a bruising battle that left the governor appearing weak and intransigent to many.

"The Mississippi miracle that he promised has not happened," Bill Minor, a longtime Mississippi newspaper columnist who was largely supportive of Mabus, said in a speech at the time.

The governor stood his ground on one too many politically contentious issues, angering many of his own supporters, Minor said in an interview. That included closing the state's three charity hospitals, which had cared for some of the poorest people in the country, and rejecting an Army Corp of Engineers plan to build a costly pump on the Yazoo River that would prevent flooding to rich delta farmland but destroy thousands of acres of wetlands in the process. The latter move cost him critical support among wealthy landowners in the delta who had supported him for his first term.

"Mabus could have gone down as one of Mississippi's great governors if he was politically astute, but that was his great weakness -- he wasn't politically astute -- and this is a hard, hard climate down here," Minor said.

Mabus never recovered and lost his re-election bid in a squeaker to Kirk Fordice, the first Republican to win the Mississippi governorship in more than 115 years. When Mabus left office in 1992, Mississippi was still ranked last in per capita income and near the bottom in most educational measures.

Where every conversation starts with the price of oil

If Mabus' time in Mississippi cemented him as a reformer, his time as ambassador to Saudi Arabia focused his reformer's eye on oil.

He was picked for the post by President Clinton, a fellow former Southern governor for whom he had campaigned in 1992. After an era of close ties with former oilman President George H.W. Bush, the Saudis made it clear they wanted a friend of the new president at the embassy.

Mabus arrived with little expertise with the Middle East, but it did not take long for him to learn one thing: Just about everything in the country revolves around oil.

"The oil minister and I had what became sort of a standard greeting between us," Mabus said. "I would say, 'Which way are prices going?' and he would say, 'Sometimes oil prices go up, sometimes oil prices go down.' And then we would get to the meat of the conversation."

During Mabus' tenure in Riyadh, from 1994 to 1996, oil prices were definitely down, averaging $17 a barrel in 1995.

For a country that gets about 90 percent of its gross domestic product from petroleum or its related products, this had far-reaching effects, according to Rutgers University Middle East historian Toby Jones.

With per capita income a third of what it had been during the high oil prices of the 1970s and social services strapped, "dissent sparked in the kingdom, especially from a few charismatic clerics who began criticizing American military personnel, including women, who were in the country, and criticizing the royal family for bringing them there," Jones said.

In late 1995, a truck bomb went off outside the U.S.-owned training center for the Saudi Arabia National Guard, killing five Americans.

"This was the very beginning," said Theodore Kattouf, who served as Mabus' deputy for a year and later became U.S. ambassador to Syria and the United Arab Emirates. "Nobody had seen anything like this before. I don't think there was a major attack on Americans in the kingdom prior to this."

Seven months later, just weeks after Mabus had left the ambassadorship, a second terrorist attack occurred at an apartment complex housing foreign military personnel, killing 19 U.S. service members and injuring hundreds more.

Today, Mabus rarely mentions his time in Saudi Arabia -- a strategic U.S. ally in the Middle East and the world's primary swing producer of oil -- when he discusses his energy initiatives. But it is not hard to read between the lines.

"We simply buy too many fossil fuels from actually or potentially volatile places on Earth," he said at an event sponsored by the Environmental Defense Fund earlier this year. "One of the things that is a vulnerability for [the Navy] is how much fuel we buy -- how much energy we buy -- from places that may not have our best interest at heart."

Planting a flag at the Pentagon

As in Saudi Arabia, oil touches nearly every corner of the Pentagon.

The United States' foremost military might is predicated on the liquid fuels that get poured into the tanks of fighter jets, ships, Humvees, drones and the generators that provide power to battlefield bases. The Defense Department uses about 340,000 barrels of fuel a day -- roughly 2 percent of total U.S. consumption.

Mabus arrived at the Pentagon in spring 2009 just as military brass were beginning to ask some of the first serious questions about the department's unquenchable thirst for fuel. The previous year's oil price spike had left the department with a roughly $20 billion fuel bill, creating a $1.6 billion budget shortfall for the Navy alone.

Although the Pentagon ultimately got that year's bill covered with supplemental and war appropriations from Congress, top officers realized that such hefty energy costs could force them to take dollars out of training or weapons budgets.

Meanwhile, fuel convoys had become a gaping vulnerability for troops in Iraq and Afghanistan. Unable to fight U.S. forces face to face on the battlefield, insurgents targeted supply lines to deadly effect. More than 3,000 U.S. troops and contractors have been killed or wounded guarding convoys in Afghanistan alone, according to DOD's numbers.

By December 2008, the Navy's top officer had scrambled together a team to develop an energy strategy.

Vice Adm. Philip Cullom, who has commanded ships during most major military interventions since the first Gulf War, was tapped to lead the effort.

For Cullom, the issue had hit home a decade earlier when he served as commanding officer of a destroyer in the Adriatic Sea during the 1999 Kosovo crisis. Cullom's ship was armed with Tomahawk missiles that he could call on to launch at targets in Eastern Europe at a moment's notice. There was just one problem: His missiles couldn't reach their targets if he was in the middle of the Mediterranean where his fuel resupply was.

"I realized then there was a bona fide reason -- a combat capability reason -- why I needed to conserve my fuel," Cullom said.

In 2008, Cullom's energy team began scanning the service for ideas and bringing forward some that had been sitting on the shelf. Since the 1990s, a lone engineer had been running a shoestring program to encourage sailors to run their ships more efficiently. A design for a hybrid electric drive that would "essentially turn ships into Priuses" was languishing, unfunded, at Naval Sea Systems Command for years. And since 2003, the Navy was doing small-scale lab tests on alternative fuels.

Some of those efforts got a cash infusion a couple of months later when Congress passed the stimulus bill, and a few months after that, Mabus arrived.

"That's when it came together," Cullom said. "There were a lot of disparate activities going on that were related to energy that were moving us in good directions, but there was no overall cohesive plan to it."

The new Navy secretary planted a flag. By 2020, the department, which includes both the Navy and the Marine Corps, will reduce its energy use and expand its portfolio to the point that it gets half its energy from alternative sources, Mabus declared.

"Big changes do not happen incrementally. Transformations happen fast, like the advent of the cellphone and the Internet," Mabus said. "I believe we are at such a tipping point with energy."

Discontent in the ranks

In the military, leadership matters.

Chuck Wald, a retired Air Force general and part of a phalanx of former military brass who are pressing for energy reform in the department since leaving the ranks, said such an effort could move at the Pentagon only if it came from the top.

"There are solutions out there -- we know what they are. It's not a matter of somebody hasn't dreamt them up," Wald said. "But unless there's a strong leader who has courage, you're not going to make it. You have to believe in doing big things. [Mabus has] got that kind of personality to take on the big issues."

But not everyone in the ranks agrees this is a good thing.

As the Marine Corps' top general from 2006 to 2010, James Conway was worrying about energy even before Mabus came aboard and had tasked the corps with devising its own strategy. His focus was on inexpensive changes that would make his force more nimble, though -- not the major market moves Mabus began pushing for when he arrived.

"When I was the commandant, I'll be honest, I said, 'Hey, boss, I can't afford to do that, there are other things that are a higher priority right now,'" said Conway, who is now retired. "But he's the guy that signs the check, so we're doing what he wants to do."

Mabus' effort to use the Navy's purchasing power to build a cost-competitive market for advanced, "drop-in" biofuels has drawn the loudest protests from Washington, D.C.'s conservatives, but the debate has been just as vigorous among defense experts who are generally supportive of his other energy programs.

With the Pentagon already absorbing nearly a half-trillion dollars in budget cuts over the next decade, there is little appetite among security hawks for new, nonessential programs. In its latest and largest purchase of biofuels, the Navy paid almost $27 a gallon, roughly seven times the price of conventional fuel at the time, although officials say they will not make large-scale operational purchases until the fuels have reached cost-parity with petroleum. And while energy efficiency measures can give ships and ground troops the greater reach that Cullom needed during the Kosovo operation, biofuels offer no direct benefit for troops.

"There is no military capability here," said James Bartis, author of a controversial RAND Corp. report that argued the military was putting too much emphasis on unproved biofuel technologies. "The ship doesn't sail any faster, doesn't sail any farther, you don't end up saving any transportation to the field, you don't save any lives using alternative fuels."

Mabus contends that there is an indirect benefit. He argues that homegrown biofuels would have a more stable price, meaning the military would not have to cut training or maintenance in order to pay for fuel when the prices spike.

"Biofuel improves warfighting ability because we can minimize the Navy's exposure to price and supply shocks," Mabus said. But, he emphasized, "biofuel is only a piece of the larger effort on alternative power, including efficiency measures, which lead to fewer convoys and fewer risky refueling missions."

Moreover, many groups concerned about the strategic vulnerability of relying on foreign oil say the Navy's effort is an important first step for the nation.

A separate study from the RAND Corp. estimates the United States spends between $67 billion and $83 billion a year to protect infrastructure and trade routes tied to oil, primarily in the Middle East.

"That's pretty much based on energy security," said Wald, the retired Air Force four-star general. "If it wasn't for energy issues, I do think we'd be in a different posture in the Middle East."

'Great Green Fleet' sets sail

In the clear blue waters off the coast of Hawaii, 22 nations with more than 40 ships and submarines are in the midst of the world's largest naval exercises. And for one day this week, three of the U.S. warships will be powered by 900,000 gallons of a biofuel blend using cooking grease and algae oil.

The "Great Green Fleet" demonstration, as the Navy calls it, will mark the first time a group of U.S. forces have engaged in operations while running on alternative fuels. It will also feature ships outfitted with energy efficiency equipment that packs a huge fuel-savings punch of its own.

From aboard the USS Nimitz aircraft carrier, Mabus plans to preside over the spectacle as biofuel-powered fighter jets take off from its deck.

But whether that picture-perfect moment goes down in history as Mabus' greatest reform victory yet or a massive overreach will be decided by Congress when he returns.

Inside the Beltway, the war of words is reaching fever pitch. Conservative groups are calling the event a "floating government boondoggle" and a "textbook example of government cronyism." Supporters are taking out television ads, organizing briefings and lining up supportive former military commanders as a Senate battle looms over whether to allow the biofuels program to move forward.

But despite the Washington uproar, some say the most important change has already been made.

While the biofuels program gets the headlines, the Defense Department has put the lion's share of its blood and sweat into initiatives that can cut energy use and take units off the grid. About 90 percent of the $1 billion that the Pentagon proposes investing in energy measures next year is targeted at reducing consumption. And those efforts have caught on where it counts most.

Two years ago, a company of Marines deployed to Afghanistan with a set of solar and efficiency gear saw dramatic cuts to the number of times it needed to be resupplied with batteries, and the gear enabled it to run two of its three forward patrol bases entirely on solar energy during the seven-month mission.

The story spread quickly within the ranks, and since then the Navy's energy office has been getting calls. Marines cannot get their hands on the equipment fast enough, and last fall the department announced plans to deploy a Navy SEAL team to Afghanistan with gear that would allow it to operate without energy or water resupply for the entirety of its mission.

Meanwhile, new recruits and officer candidates are being taught the connection between energy and military capability as part of their training, building a new generation of warriors that don't take energy for granted.

"I don't think you unlearn those lessons," Mabus said. "I'm very confident that it's becoming institutionalized and in a lot of ways it is there."