President Obama's national intelligence director, Dennis Blair, says he is resigning after 16 months in the job. In a message to his work force, Blair says his last day will be May 28. Blair's tenure was marked by intelligence failures—he took criticism over the Christmas Day bomb plot, in particular—and turf wars among the country's spy agencies. Blair, a retired Navy admiral, is the third director of national intelligence, a position created in response public outrage after 9/11. (More Dennis Blair stories.)