Question: Who is the Prime Minister of the United Kingdom whose book a thesis by John F Kennedy alludes to?

Context paragraphs:
Douglas Hofsass: Douglas Hofsass (Doug Hofsass) is a former Assistant Administrator in the United States Department of Homeland Security, assigned to the Transportation Security Administration.  In addition to his role as the Assistant Administrator overseeing risk based security and trusted traveler programs, he also served as the Federal Security Director in New York City.  As part of his responsibilities in New York City, he oversaw the first implementation of federal security operations under DHS at the Downtown Manhattan Heliport and the East 34th Street Heliport for commercial helicopter flights to John F Kennedy International Airport, Newark Liberty International Airport and LaGuardia Airport.  Hofsass also held the posts of General Manager of Commercial Aviation and Deputy Assistant Administrator for Policy and Industry Engagement for the Transportation Security Administration.  He was heavily involved in launching the TSA Pre-Check Program, and claimed a collaborative partnership with the US Customs Department and their Global Entry Program.  Hofsass served at the Transportation Security Administration from 2002 until 2013, including several years working directly for Administrators John S. Pistole, Kip Hawley and Gale Rossides.  Prior to his Federal executive service, Hofsass was with United Airlines management for nearly 10 years.  Hofsass returned to the commercial aviation sector in 2013.

JFK and the Unspeakable: JFK and the Unspeakable: Why He Died and Why It Matters is a book by theologian and Catholic Worker James W. Douglass (Orbis Books, 2008; Touchstone Books, an imprint of Simon & Schuster, 2010) that analyzes the presidency of John F. Kennedy as well as the events surrounding the assassination of John F. Kennedy.  The book is drawn from many sources, including the Warren Report.  The book's central thesis is that Kennedy was a cold warrior who turned to peace-making, and that as a result he was killed by his own security apparatus.

Winston Churchill: Sir Winston Leonard Spencer-Churchill, {'1': ", '2': ", '3': ", '4': "} (30 November 187424 January 1965) was a British statesman, army officer, and writer.  He served as Prime Minister of the United Kingdom from 1940 to 1945 and again from 1951 to 1955.  As a Member of Parliament (MP), he represented five constituencies over the course of his career.  As Prime Minister, Churchill led Britain to victory during World War II.  He led the Conservative Party for fifteen years from 1940 to 1955.

America's Choir: America's Choir: Favorite Songs, Hymns, & Anthems is a religious compilation album released by the Mormon Tabernacle Choir.  The choir was first called "America's Choir" by U.S. President Ronald Reagan.  The choir has performed at the inaugurations of United States Presidents Lyndon B Johnson (1965), Richard M Nixon (1969), Ronald Reagan (1981), George Bush (1989), and George W Bush (2001).  They also performed at the American Bicentennial, US Constitution bicentennial celebration, 2002 Winter Olympics (national anthem), and national broadcasts honoring the passing of US Presidents Franklin D Roosevelt and John F Kennedy.

Jack (cat): Jack (c. 2005 - November 6, 2011) was a Norwegian forest cat who was lost on August 25, 2011, by American Airlines baggage handlers at John F Kennedy airport before Hurricane Irene.  A campaign "Jack The Cat is Lost in AA Baggage at JFK" was started by animal lovers to help find him, with over 24,000 Friends of Jack joining the associated Facebook page.  Almost two months after he went missing, the campaign designated October 22 "Jack the Cat Awareness Day".  The cat was found shortly afterwards on October 25 but was severely dehydrated and malnourished after his 61-day ordeal.  Due to infection and injury, Jack was euthanized on November 6, 2011.

List of Prime Ministers of the United Kingdom: The Prime Minister of the United Kingdom is the head of the Government of the United Kingdom, and chairs Cabinet meetings.  There is no specific date when the office of Prime Minister first appeared, as the role was not created but rather evolved over a period of time.  The term was used in the House of Commons in 1805 and it was certainly in parliamentary use by the 1880s, and in 1905 the post of Prime Minister was officially given recognition in the order of precedence.  Modern historians generally consider Sir Robert Walpole, who led the government of Great Britain from 1721 to 1742, as the first Prime Minister.  Walpole is also the longest-serving Prime Minister by this definition.  However, Sir Henry Campbell-Bannerman was the first Prime Minister and Margaret Thatcher the longest-serving Prime Minister to have been officially referred to as such.

Jules Davids: Jules Davids (December 10, 1920–December 6, 1996) was a professor of diplomatic history at the Edmund A. Walsh School of Foreign Service at Georgetown University until his retirement in 1986.  A prolific author, his most famous work was undoubtedly his editorial assistance on "Profiles in Courage," a surprise bestseller that won the 1957 Pulitzer Prize for biography for its author, Senator John F Kennedy.  Davids received $700 for his labors and acknowledgement in the foreword that he "materially assisted in the preparation of several chapters," but extensive revelations from many sources, including a detailed account by Jules Davids himself, establish that Davids prepared initial drafts of five of the chapters on the book.

Why England Slept: Why England Slept is the published version of a thesis written by John F. Kennedy while in his senior year at Harvard College.  Its title was an allusion to Winston Churchill's 1938 book "While England Slept", which also examined the buildup of German power.  Published in 1940, the book examines the failures of the British government to take steps to prevent World War II and is notable for its uncommon stance of not castigating the appeasement policy of the British government at the time, instead suggesting that an earlier confrontation between the United Kingdom and Nazi Germany could well have been more disastrous in the long run.

Pleasant Hill, California: Pleasant Hill is a city in Contra Costa County, California, United States, in the East Bay of the San Francisco Bay Area.  The population was 33,152 at the 2010 census.  It was incorporated in 1961.  Pleasant Hill is the home of College Park High School, Diablo Valley College, John F Kennedy University, the Pleasant Hill Library and administration offices for the Contra Costa County Library system, and the Pleasant Hill Recreation & Park District.

John F Kennedy (horse): John F Kennedy (foaled 8 May 2012) is an Irish-bred Thoroughbred racehorse.  He was beaten as an odds on favourite on his debut but won his next two races, the final being the Juvenile Turf Stakes.  At the end of 2014 he was one of the antepost favourites for the Epsom Derby.

Supporting paragraphs: Why England Slept Winston Churchill
Answer: Winston Churchill