Unfriendly Fire: How the Gay Ban Undermines the Military and Weakens America is an American 2009 political book by Nathaniel Frank that argues that the "Don't Ask, Don't Tell policy banning openly gay servicemen and women from the United States armed forces weakened military and national security. According to Frank, 12,000 people — 800 of whom had previously been deemed "mission critical" by the U.S.