The Syria imbroglio looms large for Andelman, but it is just one part of a book with much broader ambitions. He wants to explore the phenomenon of red lines, track their past and present use, and distill some understanding of when they work and when they fail. As he moves from the particular to the general, he sketches a mostly dystopic world where dangerous lines are proliferating as the existing international order collapses. 'There have never been more red lines at any one point in history than today.' It is an arresting claim, but the author does not explain how he reaches it. He employs the term “red line” profligately but without a clear definition. It refers to physical borders in some contexts. At other times, he uses it to mean strong national interests or zones of influence. In still other situations, it seems to refer to international rules and norms ... One constant in Andelman’s account is a focus on military conflict, actual and potential. It is tempting therefore to view his fixation on multiplying red lines as a claim that the world is more conflict ridden or violent than in the past. If that is indeed the argument, it’s not necessarily correct ... At its best, the book serves as a competent and thorough primer on conflict or potential conflict zones around the globe.

A look at the world’s flash points for conflict, whose number seems to be growing exponentially ... Andelman’s points are sometimes too repetitively made, but the central truth holds: Everywhere around the world, people are digging in, and there’s a fight sure to come. If you’re taking bets on where the next war will break out, this is essential reading.

A lucid and concise examination of the recent proliferation of contested boundaries ('physical, diplomatic, military, all too often existential') around the world ... The book’s most vivid and eye-opening chapter tracks the history of Africa’s contested borders from European colonization in the 19th century, through U.S. and Soviet interference during the Cold War, to today’s conflicts over political ideology, religious affiliation, and access to the continent’s natural resources. Andelman moves briskly and confidently through these various hotspots, drawing on decades of experience reporting on international affairs. The result is a worthy introduction to a wide range of simmering regional conflicts that threaten global peace.