"Some weeks later the tone of these and other discussions changed. There was, by mid-July, an explicit threat that the government would, after all, seek to stop the Guardian's work and prevent publication of further material by legal means. To have resisted such action would have involved handing over ultimate control of the material to a judge and could have meant that no stories could have been published for many months, if at all. The first amendment of the American constitution guarantees its press protections of which British editors can only dream. For more than 40 years − since the publication of the so-called Pentagon papers in 1971 − it has been accepted that the state will not succeed in trying to obtain prior restraint of the press. So we will in future report this story from New York. We have shared some material with, and will collaborate with, the New York Times."
So that was the reason why the Guardian moved the reporting on the story out of the UK.
"Some weeks later the tone of these and other discussions changed. There was, by mid-July, an explicit threat that the government would, after all, seek to stop the Guardian's work and prevent publication of further material by legal means. To have resisted such action would have involved handing over ultimate control of the material to a judge and could have meant that no stories could have been published for many months, if at all. The first amendment of the American constitution guarantees its press protections of which British editors can only dream. For more than 40 years − since the publication of the so-called Pentagon papers in 1971 − it has been accepted that the state will not succeed in trying to obtain prior restraint of the press. So we will in future report this story from New York. We have shared some material with, and will collaborate with, the New York Times."
So that was the reason why the Guardian moved the reporting on the story out of the UK.