DUBAI, United Arab Emirates — The Iranian opposition leader Mir Hussein Moussavi announced the formation of a new social and political movement on his Web site on Saturday, following through on a promise made last month and defying a renewed government campaign of intimidation aimed at him and his supporters. The movement is not a political party — which would require a government permit — but a “grass-roots and social network” that will promote democracy and adherence to the law, Mr. Moussavi wrote in a statement on his site. It is to be known as the Green Way of Hope, in deference to the signature bright green color of his campaign for the June 12 presidential election, which he maintains was rigged in favor of President Mahmoud Ahmadinejad. The announcement was Mr. Moussavi’s first major public statement since the Iranian authorities stepped up their pressure on the opposition by opening a mass trial two weeks ago. Prosecutors have accused Mr. Moussavi’s campaign of links to a vast conspiracy to bring down the Iranian government. After he and many others denounced the trial, the chief prosecutor issued a stark warning that anyone questioning the trial’s legitimacy could in turn be prosecuted. Continua…