Obama's chance to end the fantasy that is Star Wars

The US has spent $160bn – only to increase the danger to itself and the rest of us

The world is still pleasurably suffering from Woah-bama whiplash. Did he really win? Are we all awake? And would anybody mind if he starts a few months early? The need for decisions is rapidly piling up – and one of Obama's first choices is whether to bring to an end one of the strangest episodes in American political history.

This is the tale of how a man with Alzheimer's Disease came up with a physically impossible fantasy based on a B-movie he once starred in – and how the US spent $160bn trying to make it come true. These billions succeeded only in making some defence companies very rich, and making Russia point its nukes at Poland and the UK once more. And if Obama doesn't decide to close this long-running farce now, it will make one more contribution to world history: the number of Weapons of Mass Destruction in the world will dramatically increase.

Here's how this story began – and continued into our time. In the early 1980s, President Ronald Reagan was increasingly worried that a nuclear war with the Soviet Union was inevitable, until a long-suppressed memory resurfaced in his mind. In 1940, he had starred in a hokey movie called Murder in the Air. He played a secret agent who had to protect a newly invented super-weapon called the "Intertia Projector", which fired an electrical current at any plane or missile approaching the US, rendering it worthless. In the film, a scientist tells Reagan that this weapon "makes the US invincible in war, and promises to become the greatest force for world peace ever discovered".

Why, Reagan wondered, couldn't he have a real Intertia Projector? Let's create a machine that would detect any incoming nuke as it approached the US and zap it into nothing! The Cold War stand-off would be over! Reagan was losing the ability to distinguish between reality and films: he repeatedly claimed he had been at the liberation of Auschwitz, when he had recreated it in Hollywood. After the Second World War, there had been a few studies trying to invent such a machine – but they all concluded it was "impossible." Nonetheless, Reagan decided in 1983 to call on America's scientists to make it happen.

Everyone was bewildered. Reagan's undersecretary of Defence, Richard DeLauer, demanded to know how such a "half-baked political travesty" got into a Presidential address. As the Pulitzer-prize winning historian Frances Fitzgerald explains: "Most of the scientists and defence experts invited to the White House expressed incredulity. An umbrella defence of the United States was a virtual impossibility... [But] when the experts insisted that science was not magic and that American technology could not do everything, they would be accused of lack of patriotism."

The lack of evidence didn't deter Reagan's team. The man he put in charge of the programme, James Abrahamson, declared: "I don't think anything in this country is technically impossible. We have a nation which can indeed produce miracles." The programme was dubbed "Star Wars" – which was fitting, since it was science fiction. As the years passed, the US strategic planners developed ever-more-fevered fantasies of how the shield would allow them to strike anywhere without any risk of retaliation.

By the time Reagan left office, there was a vast industry dedicated to chasing this will-o'-the-wisp. Huge defence contractors – including Boeing and Lockheed Martin – were making billions from it, and giving fat donations to politicians in both parties. In the decades since, the US has spent more and more, and asked the "shield" to do less and less. Now they want it to just take out a single nuke – and it still doesn't work. The tests only succeed when the interceptors know where the missile is being fired from, where it is heading to, and the warhead continually broadcasts its location to the interceptor. Some success. They have been given a near-impossible task: scientists compare it to hitting a bullet with another bullet.

But while the system's positive effects have failed to materialise, its negative consequences are real. America's strategic opponents have assumed the leading super-power couldn't possibly be spending this much on a pile of junk – so they are reacting on the assumption that the shield works. This means they are preparing bigger and more nukes, to preserve their ability to punch through the shield. They are re-targeting their missiles at Poland, Britain and the Czech Republic, the countries hosting the dud-interceptors. If they believe they are being attacked, they will destroy us first, in order to destroy the "shield" and have the ability to strike back.

US intelligence has been blunt about what will happen if the interceptors continue to be constructed. China will increase its nuclear arsenal "tenfold", India and Pakistan would "respond with their own build-ups," and Russia's "only rational response... would be to maintain, and strengthen, the existing nuclear force".

So the US has spent $160bn, only to increase the nuclear danger to itself and the rest of us. Stars Wars is a perfect example of the magical thinking that now dominates the American right. Don't like global warming? Don't worry, it doesn't exist! Don't like evolution? It's a myth! Didn't find any WMD in Iraq? They must have been shipped to Syria! Want a magical nuclear shield? If you build it, it will work!

Sure, maybe one day scientists will discover some way to evaporate nukes in the brief window before they strike. Maybe they will discover how to turn lead into gold – a pursuit that obsessed Europe's best minds for centuries. Maybe aliens will get in touch. But none of these assumptions is a sensible basis for government policy.

There is now a possibility this will end at last. After speaking to Obama on Tuesday, the Polish President Lech Kaczynski said the project was seriously in doubt. During the campaign, Obama offered a third-way dodge on Star Wars: he said he supported it but "only if the technology is proved to be workable". Well, we know it isn't workable. Obama is the first Presidential candidate of our time not to be taking money from the defence contractors. He has no political debt – but his country's is huge. Can it afford $10bn a year on this dangerous techno-trash?

In the primaries, Obama pledged to pursue real multilateral nuclear disarmament – but the shield-fantasy ensures the opposite will happen: a dramatic increase in the nukes scattered across the globe. Of course, if Obama ditches Star Wars, the neoconservatives will accuse him of "backing down" and "showing weakness". But is it really sensible to keep spending $10bn a year on an act of self-harm just to save face? The story that began with Reagan's dementia-fantasies should end with Obama's empiricism.

This decision isn't just about a bogus nuclear shield, crucial though that is. It is a test of whether the government of the United States has returned to the firm land of empirical reality – or whether it is still way out there in the blue, gasping for air among the ideological stars.

nj.hari@independent.co.uk