The turmoil of the Trump presidency has reignited interest in political violence in the USA and the potential for a new civil war. This book examines our insights about civil wars and their relevance to today's US. The book stresses how civil wars are more common in anocracies and how conflict outbreaks are promoted by overlapping cleavages, factionalism, status loss, and conflict entrepreneurs. It provides an effective synthesis, with good illustrative examples, and is engaging and accessible to non-specialists. Walter argues that the US has seen an increase in the risk factors for civil war, with an apparent decline in democracy under the Trump presidency, increasing polarization and factionalism, status loss among left-behind whites, and surveys suggesting increasing intolerance and willingness to use violence. Walter believes that the US is unlikely to see a rerun of the 19th century secessionist civil war, with organized armies, but that there is a high risk of irregular political violence such as riots and terrorist attacks, and a spiral of fear and violent countermeasures among groups both on the right and left of the political spectrum. Political violence is hardly a new phenomenon in the US, and despite insightful reflections on the US, the book is less persuasive in substantiating that political violence is becoming more common, or more likely now to escalate to civil war. Armed militias clearly predate Trump, and more died in the 1995 Oklahoma City bombing than the 2021 Congress storming. However, the discussion deserves attention, and the proposed antidotes to the risk of political violence such as institutional reform and depoliticizing elections would be valuable in their own right.