“Some experts have doubts about the missile shield concept,” as the more cautious reporters put it. (That example comes from the BBC Web site.)

A franker journalist would say that the ballistic missile defence system that the Bush administration planned to put into Poland and the Czech Republic—and that President Barack Obama has just cancelled—has never worked, and shows few signs of ever doing so.

Obama has done the right thing. It saves money that would have been wasted, and it repairs relations with Russia, which was paranoid about the system being so close to its borders. And the cancellation also signals a significant decline in the paranoia in Washington about Iran.

“Paranoia” is the right word in both cases. Iran doesn’t have any missiles that could even come within range of the  ballistice missile defence  system that was to go into Poland and the Czech Republic, let alone nuclear warheads to put on them.

According to U.S. intelligence assessments, Iran is not working on nuclear weapons, nor on missiles that could reach Europe, let alone the United States. Washington’s decision to deploy the system anyway was so irrational that it drove the Russians into paranoia as well.

Their intelligence services told them the same thing that the U.S. intelligence community told the Bush administration: that Iran had no nuclear weapons or long-range ballistic missiles, nor any possibility of getting them within less than five to 10 years. So what was the U.S. really up to, siting the system so close to Russia’s borders?

The intelligence people in Moscow also told Russian leaders that the U.S. system was useless junk that had never managed to intercept an incoming missile in an honest operational test. (All the tests were shamelessly rigged to make it easy for the intercepting missiles to strike their targets, and still they failed most of the time.)

Besides, although the planned  ballistic missile defence  base in Poland was close to Russia, it was in the wrong place to intercept Russian missiles.

So why did the Russians get paranoid about it? Because although they knew how the military-industrial complex worked in the United States (and they have similar problems with their own domestic version), they simply could not believe that the United States would spend so much money on something so stupid and pointless.

Surely there was something they were missing; some secret American strategy that would put them at a disadvantage.

No, there wasn’t, and almost everybody (except some Poles and Czechs who want U.S. troops on their soil as a guarantee against Russian misbehaviour, and some people on the American right) was pleased by Obama’s decision to pull the plug on the project.

As Dmitry Rogozin, Russia's ambassador to NATO, said: "It's like having a decomposing corpse in your flat (apartment), and then the undertaker comes and takes it away."

But why did the Bush administration choose to deploy this nonfunctioning weapons system in Eastern Europe? Indeed, the same  ballistic missile defence  system has already been installed in California and Alaska to intercept North Korean missiles that cannot actually reach the United States either. It’s as if Ford or GM designed a car with faulty steering, and decided to put it on the market anyway.

The answer lies in another weapons project that began in 1946: the nuclear-powered airplane. It could stay airborne for months and fly around the world without refueling, its boosters promised, and that would give America a huge strategic advantage.

There was only one problem. The nuclear reactor needed a lot of shielding, because the aircrew would be only feet (metres) away. The shields had to be made of lead. And lead-filled airplanes cannot fly.

Fifteen years and about  $10 billion (in today’s money) later, there was still no viable design for a nuclear-powered bomber, let alone a flyable prototype.

Ballistic missiles were taking over the job of delivering nuclear weapons anyway. But when Robert McNamara became defence secretary in the Kennedy administration in 1961, he was astonished to discover that the nuclear-powered aircraft was still in the defence budget.

It was, he said, “as if I came down to breakfast in the morning and found a dead walrus on the dining-room table”.

It took McNamara two more years to kill the program, against fierce opposition from the air force and defence industry. The fact that the nuclear-powered aircraft did not and could not work was irrelevant.

Former general Dwight D. Eisenhower’s presidency is perhaps best remembered for his warning against what he named the “military-industrial complex” in his farewell speech in 1960, but he actually gave two warnings.

The other was that “public policy could become the captive of a scientific-technological elite.” These were the lobbies that kept the nuclear airplane going for  17 years, and they have kept the  ballistic missile defence  system going for more than a quarter-century already.

President Obama has killed the most pointlessly provocative of the ballistic missile defence  deployments, but he still cannot take the political risk of admitting that the system doesn’t work (though he twice explained in his speech that the United States needed missile defence systems that were “proven and cost-effective”.)

It is the grandchild of Star Wars, a sacred relic blessed by Saint Ronald Reagan himself, and it will keep appearing on various dining-room tables for years to come.

Gwynne Dyer’s latest book, Climate Wars, was published recently in Canada by Random House.