The Chicago Tribune ran an interesting article entitled The Evolution of the Thriller about the resurgence of the thriller as a popular genre in the post 9/11 world. According to Brad Thor, the author of the bestseller Full Black, the time period after the Cold War through the 1990s was a stagnant period for the thriller genre. 9/11 gave readers and writers a common, well-defined enemy back. Gone are the spy novels and simmering tension of superpowers of the mid-twentieth century replaced instead by detailed novels about military hardware and modern spycraft. According to author David Morrell, thrillers are the most popular form of reading in the past 10 years. Other books mentioned in the article include Rules of Betrayal by Christopher Reich and Die Twice by Andrew Grant. The article also pays homage to some classic gems of the genre including The Thirty-Nine Steps by John Buchan, The Spy Who Came in From the Cold by John Le Carre, The Tears of Autumn by Charles McCarry, and Absolute Power by David Baldacci.