WASHINGTON (Reuters) - President George W. Bush on Tuesday said Iran had a right to a civilian nuclear program if it did not gain expertise or materials to build an atomic weapon. The United States is concerned that Iran's nuclear program is aimed at producing weapons, and Bush said he would be "speaking candidly about Iran" with Chinese President Hu Jintao and Russian President Vladimir Putin, who are gathering in New York for the United Nations General Assembly. "It is very important for the world to understand that Iran with a nuclear weapon will be incredibly destabilizing," Bush said at...