WASHINGTON, Aug 14 (AFP) - The families of more than 600 US troops in Iraq have launched a campaign for their return, bitterly criticizing President George W. Bush's reasons for going to war and what they see as his belittlement of the risks. "George Bush said, 'Bring them on,'" said Nancy Lessin, co-founder of Military Families Speak Out, referring to the president's response to post-war attacks on US troops occupying post-war Iraq. "Those three words galvanized Military Families Speak Out, Veterans for Peace and other veterans' organizations to initiate the campaign we are launching today," she said. "We say, 'Bring...