As space becomes more crowded with nearly 10,000 active satellites operated by over sixty countries and hundreds of private companies, preventing conflict in this strategic environment has become increasingly important. The Politics of Space Security examines the history of the space age from its origins in national rocket programs of the 1920s and 1930s to the present day, focusing in particular on the political, military, and diplomatic challenges affecting space security. James Clay Moltz analyzes the competing demands of national interests in space against the shared interests of all spacefarers in preserving the safe use of space in the face of emerging threats, such as man-made orbital debris. Since the publication of the first edition in 2008, this book has become recognized as a key source on the political history of the space age. The fourth edition updates the book's coverage to include the period from 2019 to 2025. Major commercial developments in these years are examined-such as the orbiting of SpaceX's Starlink mega-constellation-as well as initiatives in space diplomacy and threats posed by growing military counterspace programs. Additionally, Moltz updates the academic literature to include significant works on space security published since the first edition.