North Korea l where is the " powerful " United states of America

Where is the " powerful " United states of America who knows how to bark and bite only the innocent muslim Arab nations but can't bark and bite own dog? .... US fighting the less populated middle east alone does not make them the most powerful nation ...The reason the United states of America gave for attacking Iraq , killing Saddam Hussain and his entire family and killing over two million innocent civillians was that Iraq has Nuclear weapon .... Why can't the US also attack and kill the North Koreans for possessing the Nuclear weapon? ... Or are they fighting only the Arabs because they're muslims and not christians? ... If they refuses to fight North Korea , i will believe that the United States of America are nothing but Terrorists .... Infact , they're the only terrorists nation on earth ... So , for world peace , North Korea must wipe the United states from the surface of the earth!