Iranian President Mahmoud Ahmadinejad insisted Thursday that Tehran's nuclear program is peaceful and said he is "at a loss" about what more he can do to provide guarantees. "The bottom line is we do not need a bomb," he said at a news conference on the sidelines of the U.N. General Assembly. Ahmadinejad said his country has not hidden anything and was working within the framework of the Nuclear Non-Proliferation Treaty. With world leaders gathered at the United Nations, the United States had hoped to move decisively this week toward political and economic sanctions against Iran after it missed an...