Answer
The Nivelle Offensive was a disastrous French attack in April 1917 that resulted in heavy casualties and a loss of morale among the French troops. General Robert Nivelle, the commander of the French army, had promised a quick and decisive victory but failed to deliver, leading to his replacement by General Philippe Pétain. Pétain adopted a more cautious approach, emphasizing defensive tactics and restoring the morale of the French army.