Manssor Arbabsiar says US invented the plot as a political tool
                                
                                
                                    (Newser) -
                                    The Iranian-American accused of  conspiring to kill  the Saudi Arabian ambassador to the US pleaded not guilty today at a federal court. Manssor Arbabsiar, 56, faces charges of conspiracy to murder a foreign official, conspiracy to use a weapon of mass destruction, and conspiracy to commit an act of terrorism,...