The nation's top intelligence officer, director of National Intelligence Dennis Blair, announced his resignation Thursday after months of friction and repeated duels with White House officials. WASHINGTON — The nation's top intelligence officer, director of National Intelligence Dennis Blair, announced his resignation Thursday after months of friction and repeated duels with White House officials. The retired Navy admiral gave no reason for his departure in his public statement, nor did he express thanks to President Obama for the opportunity to serve in his administration. A U.S. official indicated Obama had asked Blair to resign, saying a job search was well...