How did the Nivelle Offensive lead to mutinies in the French army?

The Nivelle Offensive, launched in April 1917, led to widespread mutinies in the French army primarily due to the catastrophic failure of General Robert Nivelle’s military strategy and the resulting collapse of troop morale.12

Nivelle had made overly optimistic, widely publicized predictions that his plan—which relied on intense artillery bombardments followed by massive frontal assaults—would achieve a decisive breakthrough. However, the German army had anticipated the offensive and strengthened their defenses, rendering Nivelle’s tactics ineffective. The French assault on the Aisne front resulted in a fiasco, with troops trapped by machine-gun fire and suffering approximately 120,000 casualties for minimal territorial gain.12

The mutinies began in late April as exhausted soldiers were ordered back into the line. The unrest spread to 16 French army corps, with soldiers signaling their grievances through cries such as, "We’ll defend the trenches, but we won’t attack". The crisis was only resolved after Nivelle was replaced by General Philippe Pétain, who restored order by addressing the soldiers' grievances and promising to avoid future reckless, suicidal offensives.21