History is replete with leaders drawing real or metaphorical lines in the sand, challenging opponents to cross only if they dare. David Andelman, an American journalist and author, believes that one way to understand global risks and challenges is to explore the nexus of red lines that define global politics.

Indeed, Andelman—in this episode of New Thinking for a New World and in his recent book A Red Line in the Sand: Diplomacy, Strategy, and the History of Wars That Might Still Happen—argues that never before have global affairs been so entangled by red lines. Moreover, he says that Donald Trump made everything worse. Can we recover without a catastrophe?