THE campaign against the Son of Star Wars missile defence project was last night dealt a massive blow when the U.S. withdrew from the 1972 Anti Ballistic Missile Treaty.

The announcement by President George W Bush will come into effect in six months time. The move gives the Pentagon a green light to forge ahead with the controversial missile defence system - which could involve North Yorkshire bases RAF Fylingdales and Menwith Hill.

It also shows American determination to press ahead with the project in the face of widespread opposition.

The announcement was immediately branded a "mistake" by Russian President Vladimir Putin.

And North Yorkshire-based opponents of Bush's missile defence plans warned it would risk world safety.

"President Bush has for some time made it quite clear that he was going to step outside of the treaty," said Anni Rainbow, a campaigner against U.S. spy base Menwith Hill and the Son of Star Wars project.

"The world is a sorrier place, and certainly a more dangerous place, because of that."

But President Bush said: "I have concluded the ABM treaty hinders our government's ability to develop ways to protect our people from future terrorist or rogue-state missile attacks."

He has told Mr Putin that the two leaders have six months to fashion a compromise that eluded them in talks in Washington in November.

President Bush insists the ABM treaty is outdated, with Russia no longer an enemy, while states like North Korea and Iran are ambitiously pursuing weapons of mass destruction that could in a few years threaten the United States.

Downing Street said President Bush's move to pull the United States out of the treaty reflected a rapidly changing global security situation.

The Prime Minister's official spokesman said: "In terms of reaction, I think we should leave it primarily to the two countries involved because it is a bilateral matter between the two of them."

Earlier this week, Tory leader Iain Duncan Smith said he did not believe Fylingdales or Menwith Hill would be involved in the controversial project.

Updated: 10:48 Friday, December 14, 2001