A couple of decades ago a young Tory wannabe policy analyst wrote a pamphlet called Greening the Tories. It was an attempt to argue that being in favour of environmental protection and energy conservation was not necessarily a liberal or statist idea.

Conserving is, well, conservative. Keeping the air clean, cars efficient and energy affordable benefits everyone, regardless of ideology. Why, in any case, should conservatives be so hostile to environmentalism? If done right — with market incentives and smarter technology rather than with crude regulation — it could be a conservative vote-winner.

Well, the idea didn’t get far. I wrote the pamphlet more as a thought experiment than as a blueprint. But if you live long enough even too-clever-by-half post-adolescents can find solace.

So here’s a simple question: who do you think are now advocates for new energy technologies and environmental regulation? Here’s the surprising answer from America: a motley collection of neocon hawks, Christian evangelicals and right-wing isolationists.

Take the hawks first. Some key advocates for the war against Saddam Hussein — among them Frank Gaffney, the neocon fire-breather, and James Woolsey, a former CIA chief — have come out as born-again conservationists, dedicated to promoting green technologies that can liberate the US from near-complete reliance on oil imports.

The primary motivation is to reduce Saudi support for terror, funded in large part by America’s petrol-hungry economy. In Gaffney’s words: “It is neither in the United States’ strategic, national security nor economic interests for this country and other industrialised nations to continue relying on imported oil from those who wish to do us harm.”

It’s a little easier for Americans to cut oil consumption than to send hundreds of thousands of troops to reform every oil-based Arab autocracy.

Now take the evangelicals. As the Christian right matures it has begun to see global issues in surprising ways. Evangelicals have been prime movers in the Bush administration’s Aids policy in Africa, in policies designed to end slavery, and even stopping the genocide in Darfur.

Lately, many evangelicals have also begun campaigning for what they call “creation care”. “Environmentalism” sounded too hippie for their tastes.

Mankind, they argue, has a duty to be a good steward of God’s world. And that means energy conservation. “The environment is a values issue,” the Rev Ted Haggard, president of the 30m-member National Association of Evangelicals, recently told The Washington Post. “There are significant and compelling theological reasons why it should be a banner issue for the Christian right.”

The evangelical magazine Christianity Today editorialised last autumn that “Christians should make it clear to governments and businesses that we are willing to adapt our lifestyles and support steps towards changes that protect our environment”.

A hefty proportion of the American right — despite the caricatures in the European press — is leery of foreign entanglement as well. Isolationist tendencies lead inexorably to the product that most ties the US to the turmoil-ridden Middle East: oil. The tipping point may well be the recent — and possibly permanent — increase in the price of petrol.

A USA Today poll last week found 58% of Americans saying that higher petrol prices were eating into their standard of living. Expensive petrol may also be behind the recent slide in the president’s approval rating to a historic low for re-elected presidents.

These groups have now allied with more traditional environmental lobbies to form an organisation called Set America Free. (They have a website at www.setamericafree.org.) What do they propose? There are competing ideas. Among them: tax credits for researching new forms of energy; more government research into alternatives to oil; more nuclear power; more exploitation of domestic oil and coal reserves; higher taxes on petrol; encouragement of hybrid car technology.

Fareed Zakaria, of the magazine Newsweek, recently called for direct presidential action: “Tomorrow, President Bush could make the following speech, ‘It is now possible to build cars that are powered by a combination of electricity and alcohol-based fuels, with petroleum as only one element among many. My administration is going to put in place a series of policies that will ensure that in four years, the average new American car will get 300 miles per gallon of petroleum. And I fully expect in this period to see cars in the United States that get 500 miles per gallon’.”

The beauty of this policy is that it backs both more exploration of domestic oil and a ramped-up effort to popularise hybrid cars and other forms of energy. The Middle East’s troubles have built support for this. But so has the growing understanding that oil may be headed for a permanent, more expensive plateau as China consumes more and more of it.

The whole world stands to gain. Not only would the policy switch reduce carbon gases that may well be contributing to global warming. It would also help defuse a looming global superpower fight between China and the US over oil supplies.

Does this movement have a future? That’s hard to tell. John Kerry made energy independence a key plank of his presidential campaign — and, of course, he lost. What was needed was a more bipartisan approach, one that appealed both to liberal environmentalists and conservative hawks.

Now we have the first signs of one, with grassroots power from the bases of both political parties — greens for the Democrats, evangelicals for the Republicans.

I’m doubtful whether the critical impetus for new research and development — a big rise in petrol taxes — will be implemented in the near future. But more federal research, presidential leadership and some new tax credits cannot hurt. Hybrid cars are beginning to catch on — and more expensive petrol is beginning to make them more economical for ordinary Americans.

Ideas can last for decades without coming to fruition. It takes luck and a fortuitous combination of factors to bring them to life.

Between them, the Christian and neocon right, the enviro-left, and the mullahs of the Middle East may finally achieve what a young Thatcherite once dreamt of. The geo-neocon-green movement may have arrived. Just in time.