This book represents the culmination of a project that began in the fall of 1975 when a working group of the American Society of International Law was convened under the direction of Professor Evans and myself in order to prepare a study for the Department of State. The report of the working group was submitted to the Department of State on September 1, 1977. The book is a revised, expanded, and updated version of that report. In addition to serving as co-director of the working group and as co-editor of the report and the book, I was a primary or sole author of the following parts of the book: the preface, pp. xv-xix; the acknowledgments section, p. xiii; the introduction, pp. xxiii-xxxviii; the chapter on "Protected Persons and Diplomatic Facilities," pp. 277-339; the chapter on "State Self-Help and Problems of Public International Law," pp. 553-73; and the appendix, which summarizes the conclusions and recommendations of the project and their support rationale, pp. 633-68.