As soundbites go, it was inspired. “Americans are addicted to oil,” George W Bush announced in his state of the union speech last week, before pledging to break his country’s reliance on Middle East oil exports by 75%. In one move Bush had achieved the seemingly impossible: simultaneously delighting both the environmentalist lobby as well as the right-wing neocons who fear America’s growing dependence on foreign oil.

It won an instant round of applause and played well in the media. But then came the questions: how could America achieve such a target? Who would pay for it? And how would the Middle East react to the threat of losing one its biggest markets? For some environmentalists there was a rich irony in Bush’s answer to the first of those questions. His big idea was to replace America’s addiction to oil with another: to alcohol.

It sounded just the kind of scientific solution that Americans love — lots of high technology and no need to sacrifice their cars — but for the more seasoned White House observers it all had a ring of familiarity. Was it too good to be true? It was just three years ago, for example, in his 2003 state of the union address, that Bush made an almost identical promise to cut the nation’s reliance on oil. Then, however, his miracle fuel for the future was not ethanol — industrial alcohol — but hydrogen. “The first car driven by a child born today could be powered by hydrogen,” he said, as he pledged £800m for new research.

Three years later and that dream looks no closer than it did then. What’s more, as Andrew Sullivan points out, there is a long history of similar pledges going right back to the time of Richard Nixon.

In 1973 America imported just a third of its oil. By 1998 that hit the psychologically crucial threshold of 50% and has since reached 55%. What’s more, most of that rise is down to transport, especially cars. Of the 20m barrels of oil consumed each day by America, about 14m go to road users. This is predicted to reach 21m barrels over the next 20 years.

If it does, transport for Americans will consume about 75% of the US oil supply and about a sixth of the whole world’s. Inevitably, an increasing proportion of that will have to come from the vast reserves in the Middle East.

Bush’s administration has long been aware of these figures and one sign that it was already turning on its axis over oil came shortly before Christmas. Donald Rumsfeld, the defence secretary, who presides over the least green department in government, was in an ebullient mood at a holiday party. Nora Maccoby, a screenwriter who is described by the tabloids as an “eco-babe”, began lecturing him about the importance of energy independence to America’s national security. Rumsfeld not only listened, he grinned to others: “I can’t believe this — this girl’s kicking my ass and she’s right.”

He told Maccoby: “Call the secretary of energy. You can use my name.” Later he went on to send a “snowflake” about the issue: a memo to colleagues about ideas that he thinks will “snowball”. To the amazement of environmentalists, it is becoming patriotic in America to care about the environment.

The “green hawks” — neoconservatives who are for the Iraq war and against dependence on Middle Eastern oil — are also on the march. Fighting terror abroad while guzzling petrol at home is a self-defeating exercise, they argue. Iran is able to thumb its nose at the international community over its nuclear programme because of the world’s thirst for the black gold, while the mosques and madrasahs where jihadists foment their plots against the West have been built by Saudi petro-dollars.

Ever since September 11, 2001, Bernard Lewis, the Islamic scholar and intellectual guru of the neoconservative movement, has argued against overdependence on oil. In his view it has been responsible for turning the austere religious tenets of an obscure Saudi tribe — the Wahhabis — into a worldwide Islamic fundamentalist revival. “There is only one solution and that is to find another source of energy besides oil,” Lewis said at a meeting at the Hudson Institute, a conservative think tank.

James Woolsey, former director of the CIA and a prominent supporter of a green hawk organisation called Set America Free, says that the United States is “fighting a war against terror and paying for both sides”. But he still describes the new environmental movement as “a coalition of tree huggers, do-gooders, hawks and evangelicals”. Joining this mix are America’s legions of four-wheel-drive car owners, who believe a tank of cheap petrol is every patriotic American’s birthright.

Faced with this coalition, Bush is turning to technology for a solution. But what are those technologies? Can alcohol save American motoring or is hydrogen the answer? Or is the real answer that Americans should learn to live like the rest of the world and simply use their cars less? The most obvious place to find answers ought to be the car manufacturers themselves, but at the moment they are also confused. At Honda, Ed Cohen, its North America vice-president of government affairs, is placing multiple bets. In the short term the company has committed itself heavily to hybrids, cars powered by a combination of a petrol engine and electric motors. These offer big efficiency savings and are likely to be the cleanest cars in mass production for several years.

In the longer term, however, the company’s hopes rest on a prototype car which is currently being driven around Los Angeles by the Spallino family. Their every move is carefully monitored to see if the car meets a family’s daily needs. Powered by hydrogen, the vehicle emits nothing more than steam as it glides through the city streets. There are, however, a host of problems to solve, of which the most important is how to source the hydrogen. If it is extracted from hydrocarbon fuels then the system overall can produce just as much greenhouse gas as an ordinary car, making it all rather pointless.