Director of National Intelligence James R. Clapper is telling Congress that Islamic militants will continue plotting against U.S. interests overseas and homegrown attacks will pose the most significant threat to Americans at home. In his opening statement Tuesday to the Senate Armed Services Committee, Clapper says the perceived success of attacks by homegrown violent extremists in Europe and North America — such as those in Chattanooga, Tennessee, and San Bernardino, California — might motivate others to replicate the attacks.