At this point one hundred years ago, America was entering WW1, the French were starting a wave of mutinies (more like strikes by soldiers) and the Nivelle Offensive was lurching into failure.
Despite roughly three years of ineptitude, the French from Nivelle on down to the lowest commissioned officer thought if they shelled the Germans enough, they would not hold their lines. The sad thing is that the French had poor recon, the Germans had switched to their flexible defense in depth and the underground tunnels and rooms of the Germans made the shelling by the artillery ineffective.
The French waited maybe a few minutes after the artillery stopped and sent out the troops to march into what they thought were decimated German defensive positions. The French advanced slow despite the Germans abandoning their most forward lines. No man's land was still hell with barbed wire and chewed up earth. Eventually the French walked into German machine gun nests. Some French troops even passed underground chambers that they knew nothing about, so that the Germans could then fire on them from two directions and trap them.
When the Germans counterattacked, the French were thrown into chaos. Their saving grace was that the French artillery could continue shelling and pin other Germans down and prevent them from joining the attack. Even the introduction of tanks did not help. The French tanks were lighter than the British ones, and were taken out by German artillery, creating colorful burst of flames in the grey and brown muck. Some tanks were not as long as the trenches they were to roll over, therefore they fell into the trench.
In that first day of the offensive, the French gained maybe a hundred or two hundred yards of territory. Germans had stopped them and inflicted many more casualties on the French than the French ever expected. The French mutinies were with good reason. While dozens of mutineers were shot by Petain who took over for Neville, Neville was sacked, troops were given more rest and an entirely new strategy was formed.