Nivelle's attack (the Second Battle of the Aisne) failed to achieve its main war-winning objective. At the cost of very high casualties, the offensive exhausted the German reserves and conquered some tactically important positions. A French tank attack had also been launched near Berry-au-Bac but half of the Schneider CA1 tanks engaged were knocked out. Nivelle was removed from his command on 15 May 1917 and was replaced by General Philippe Pétain. A similar battle would have been considered a draw in 1915 but in 1917, after the huge losses at the Battle of Verdun and the Battle of the Somme, the psychology of the soldiers was fragile. The strategic failure and the casualties caused a collapse in the morale of the French infantrymen, who had been so enthusiastic just a few days before. The U.S. entry into the war in early April 1917 was met with euphoria in France.