Since the 1970s, Azéma emerged as a critical voice in the historiography of France's Vichy regime, systematically dismantling the comforting narratives that the French had used post-war. He was the son of a man labeled as a collaborator, yet he fearlessly addressed the complexities and moral dilemmas of the era. In his seminal work, "From Munich to the Liberation," published in 1979, he condemned the Vichy regime, calling it a "phony regime" and criticizing its leader, Marshal Philippe Pétain, for embodying a dangerous mix of nationalism and elitism.

Azéma's meticulous analysis laid bare the multifaceted and often opportunistic nature of Vichy's factions, challenging the dominant perception of Pétain's government as benevolent. His writings resonated widely in France, surpassing even his colleague Robert O. Paxton's influential works in sales. Through his contributions, Azéma not only participated in historical analysis but also influenced public perception and understanding of a painful chapter in French history. His legacy continues to inspire future generations of historians to confront uncomfortable truths in the pursuit of historical accuracy.