One of the potentially most damaging events for the Allied forces during the First World War were the French Army mutinies which started just after the disastrous Second Battle of the Aisne, the main action in the Nivelle Offensive in April 1917. General Robert Nivelle had promised a decisive war-ending victory over the Germans in 48 hours but the shock of failure soured their mood overnight. The mutinies and associated disruptions involved, to various degrees, nearly half of the French infantry divisions stationed on the western front. The new commander General Philippe Pétain (pictured right) restored morale by talking to the men, promising no more suicidal attacks, providing rest for exhausted units, home furloughs, and moderate discipline. He held 3,400 courts martial; 554 mutineers were sentenced to death but over 90% had their sentences reprieved. The mutinies had ended by 10th June but were kept secret from the Germans and indeed the rest of the world until the danger had long past.
The French army was bending under the strain of the war that had taken its huge toll on the nation since 1914. As a result the new plan of Petain and Foch was a rigid defensive, with the exception of a few limited attacks to assist the British during their forthcoming Ypres offensive, until the Americans would be ready in 1918. Behind this defensive they would build up the army and an immense accumulation of material including artillery, tanks and the air fleet.