Tom Clancy - Line of Sight

On a break between missions, Jack Ryan Jr is asked by his mother to visit Sarajevo and track down a girl whose life she saved during the Bosnian War. Finally, he thinks, life might be quietening down. That's until he meets Aida, grown from a child into a beautiful and selfless woman. He finds himself drawn to her, not to mention impressed by her dangerous work helping Syrian refugees enter Europe. Heart-stopping action.