American officials have called the incident a mistake and issued a series of apologies. Afghan President Hamid Karzai has urged calm, saying that Afghans should not let the insurgents capitalize on their indignation to spark violence. Monday's attack appeared to be a sign that the Taliban are seizing the opportunity to do just that. The bomber drove up to the gates of the airport – which serves both civilian and international military aircraft – shortly after dawn and detonated his explosives...