The top U.S. military official responsible for defending the nation against a North Korean nuclear strike said he is "concerned" about the Pentagon's ability in the future to defend the nation against a limited attack. Gen. Glen VanHerck, head of U.S. Northern Command, told the House Armed Services Committee that while he has confidence in the ability of the Ground-based Midcourse Defense system to counter North Korean threats today, he is less sure about the ability of the nation’s main...