Donald Trump said I had nothing to say. I do. My son Humayun Khan, an Army captain, died 12 years ago in Iraq. He loved America, where we moved when he was 2 years old. He had volunteered to help his country, signing up for the ROTC at the University of Virginia. This was before the attack of Sept. 11, 2001. He didn’t have to do this, but he wanted to.