By Megan Mayhew Bergman, Special To The Washington Post Viet Thanh Nguyen’s new collection of stories, “The Refugees,” is as impeccably written as it is timed. The book, a follow-up to Nguyen’s Pulitzer Prize-winning novel, “The Sympathizer,” is dedicated to “all refugees, everywhere.” This is an important and incisive book written by a major writer with firsthand knowledge of the human rights drama exploding on the international stage — and the talent to give us inroads toward understanding it. Nguyen’s acknowledgments do not shy away from his relationship to the book’s title.