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.

The book was originally intended to be no more than a college thesis – it was rated as a magna cum laude by Professor Henry A. Yeomans and as a cum laude plus by Professor Carl J. Friedrich. Kennedy's father, Joseph P. Kennedy, Sr., always keen to elevate his son's reputation, encouraged Kennedy to publish the book, enlisting Henry R. Luce to write the foreword, and his friend Arthur Krock, former bureau chief of the New York Times, to assist in redrafting Kennedy's college thesis into what became Why England Slept. Author Garry Wills claims that this assistance amounted to rewriting and retitling the manuscript, as well as finding an agent for its publication.

As ambassador to Britain, Joseph P. Kennedy Sr. supported Prime Minister Neville Chamberlain's policy of appeasement during the late 1930s. John F. Kennedy lived with his father in Britain at that time and later, during World War II, since 1940, witnessed the Luftwaffe's bombings of Britain first-hand.

The book's foreword was written by Henry R. Luce. Joseph Kennedy had initially approached Harold Laski to write the foreword but Laski declined, feeling that it was "the book of an immature mind; that if it hadn't been written by the son of a very rich man, he wouldn't have found a publisher."