The years when John Diefenbaker’s Progressive Conservatives were in office were among the most tumultuous in Canadian history. Variously branded as a populist, maverick, and “Rogue Tory,” Diefenbaker came to power on a surge of optimistic nationalism in 1957. By the time of his electoral defeat in 1963 he had stirred up more controversy than any previous prime minister. This was nowhere more apparent than in his handling of international affairs, particularly Canada’s relationship with the United States. This book reassesses foreign policy in the Diefenbaker era to determine whether its failures can be mainly attributed to the prime minister’s personality traits, particularly his indecisiveness, or whether broader underlying shifts in world affairs were to blame. Written by leading scholars who mine new sources of archival research, the chapters examine the full range of international issues that confronted Diefenbaker and his ministers and probe the factors that led to success or failure, decision or indecision, on specific issues. The introduction and conclusion set these case studies in the broader context of world events during the 1950s and ’60s. Together, the chapters in this book demonstrate that underlying structural changes were largely responsible for the extraordinary tumultuousness of the Diefenbaker era. Rather than dismissing him as a “Rogue Tory” on the world stage, this fascinating reconsideration of the Diefenbaker years challenges readers to push beyond the conventional and reassess his record with fresh eyes.