Military Alliances in the Twenty-First Century is the first book to explore fully the politics that shape these security arrangements – from their initial formation through the various challenges that test them and, sometimes, lead to their demise. Across six thematic chapters, Alexander Lanoszka challenges conventional wisdom that has dominated our understanding of how military alliances have operated historically and into the present. Although military alliances today may seem uniquely hobbled by their internal difficulties, Lanoszka argues that they are in fact, by their very nature, prone to dysfunction.