[6] Explaining that "(h)istory does not repeat, but it does instruct,"[7] he analyzes recent European history to identify conditions that can enable established democracies to transform into dictatorships.

[8][9] The short (126 pages) book is presented as a series of twenty instructions on how to combat the rise of tyranny, such as "Defend institutions", "Remember professional ethics", and "Believe in truth".

[10] Carlos Lozada of The Washington Post describes the book as "clarifying and unnerving", "a memorable work that is grounded in history yet imbued with the fierce urgency of what now.

"[11] Daniel W. Drezner, writing for The New York Times, says, "For such a small book, Snyder invests On Tyranny with considerable heft," but he also describes it as "overwrought" and tending toward hyperbole.

[15] He notes that On Tyranny was written in a defensive mode and that if its lessons are learned and implemented now things could get much better in 2025 for those who want to maintain democracy and the rule of law in the United States.