David Michael Letterman (born April 12, 1947) is an American television host, comedian, writer, and producer.
 He hosted a late night television talk show for 33 years, beginning with the February 1, 1982 debut of "Late Night with David Letterman" on NBC, and ending with the May 20, 2015 broadcast of "Late Show with David Letterman" on CBS.
 In total, Letterman hosted 6,028 episodes of "Late Night" and "Late Show", surpassing friend and mentor Johnny Carson as the longest-serving late night talk show host in American television history.
 In 1996 Letterman was ranked 45th on "TV Guide"' s 50 Greatest TV Stars of All Time.
Against All Enemies is a 2011 spy novel by Tom Clancy and Peter Telep.
 It appears not to be part of the Jack Ryan series of novels, and instead introduces a new hero, ex-Navy SEAL and CIA paramilitary operations officer Maxwell Moore.
 Although, at the end of this novel, a character from the Jack Ryan series of novels (Dominic Caruso) attempts to recruit Maxwell Moore into the Campus.
Daniel Joseph "Dan" Lauria (born April 12, 1947) is an American television, stage, and film actor.
The Battle of Takusa was fought on April 12, 1853, between the forces of Kassa Hailu, future Emperor of Ethiopia, and an alliance of several rival warlords.
 The forces of Hailu's enemies were led by Dejazmach Birru Aligaz, who was reinforced by troops sent to him by Wube Haile Maryam under the command of his son, Gwangul Wube.
James E. Tierney (born April 12, 1947) is an American attorney, lecturer in law, and founding director of State AG, an educational resource on the office of state attorney general.
 He served as Attorney General of Maine from 1980 until 1990.
Lawrence T. "Larry" Cannon (born April 12, 1947) is a retired American basketball player, a former 6'5" (1.93 m) guard born and raised in Philadelphia.
 At Lincoln High, he set scoring records that stand to this day.
 Cannon scored more points all-time than any Philadelphia high school player not named Wilt Chamberlain.
Alexander "Alex" Briley (born April 12, 1947) is an American singer, who performs the "G.I." role in the disco music group Village People.
 Briley was born and raised in Harlem, New York, and later Mount Vernon, New York.
 A minister's son, he sang in church from an early age and studied voice at the University of Hartford.
Giuseppe Nicola Summa, known as Ninco Nanco (April 12, 1833 - March 13, 1864), was an Italian brigand.
 One of the most important brigands after the Italian unification, he was a lieutenant of Carmine Crocco, band chief of the Vulture area, in Basilicata.
 He was known for his brilliant guerrilla warfare and for his brutality against his enemies.
Thomas Leo "Tom" Clancy Jr. (April 12, 1947 – October 1, 2013) was an American novelist best known for his technically detailed espionage and military-science story lines set during and after the Cold War.
 Seventeen of his novels were bestsellers, and more than 100 million copies of his books are in print.
 His name was also used on movie scripts written by ghost writers, nonfiction books on military subjects, and video games.
 He was a part-owner of the Baltimore Orioles and vice-chairman of their community activities and public affairs committees.
Allan "Bud" Gulka (born April 12, 1947) is a Canadian former professional ice hockey player.

Question: Which writer of Against All Enemies was born April 12, 1947?
Answer: Tom Clancy