This book is the product of archival research in Nanjing and Taipei. Friends and colleagues in both places contributed in many ways to its gestation. In Nanjing, Chen Qianping, Guan Yumin, and Chen Rangzhi were hosts of rare generosity who made sure that my family was made at home and my research time productive. Zhang Xianwen, Cai Shaoqing, Chen Hongmin, and Shen Xiaoyun of the History Department at Nanjing University all helped me in countless ways. At the Second Historical Archives of China, Ma Zhendu ensured a steady supply of documents and enlightened me about many aspects of KMT history. In Taipei, the Institute of Modern History provided accommodation and an office, and a profoundly stimulating academic environment, which has saved me from many errors of fact and interpretation. I am profoundly grateful to its directors during my stay, Ch'en San-ching and Lü Fang-shan. Chang Jui-te was a superior guide to Republican military history and Ch'en Yung-fa a delightful source of insight into many obscure aspects of Republican history, including personal backgrounds and relations. Shen Huai-yu, Lin Man-houng, Chen Tsu-yu, Chu Hung-yuan, Yu Miin-lin, and Chang Ning all were generous in sharing their expertise. Much of my time in Taipei was spent in archives. The staff of the KMT archives, then still at Yangmingshan, and the Academia Historica went beyond the call of duty to assist me in deciphering difficult handwritten documents.
At Cambridge, it has been my good fortune to be surrounded at St Catharine's College by a group of outstanding historians. I am especially thankful to Chris Bayly for his support for this project and his insightful comments on successive drafts of the manuscript. John Thompson shared his knowledge of US foreign policy and the Second World War, asked pertinent questions, ensured that I kept on a manageable track, and supplied a stream of Churchill anecdotes. In the wider Cambridge community, David Reynolds provided important corrections to my chapter on Joseph Stilwell, while at the Faculty of Oriental Studies Mark Lewis, Boping Yuan, Susan Daruvala, and Stephen Large not only were tolerant of a distracted colleague but also provided important help with various major and minor aspects of my research. Further afield, Stephen MacKinnon, Diana Lary, and Arthur Waldron invited me to participate in always stimulating and friendly meetings of an informal group of China historians interested in warfare. I have benefited greatly from comments on the manuscript by Bruce Reynolds, Joseph Yick, Timothy Cheek, Diana Lary, Susan van de Ven, and Denis Showalter, as well as from opportunities to present parts of the research at conferences and seminars at Nanjing University, the Institute of Modern History of the Academia Sinica,