Timeline: WW I Central Powers Victory The Nivelle Offensive was a 1917 Allied attack on the Western Front. The assault was advertised to win the war within 48 hours. French generals also expected to only lose 10,000 casualties during the battle. The reality was far different. The Nivelle Offensive was a three stage plan: April 9, 1917 Battle of Arras The British 12th Division attacks Observation Ridge. At the same time, the 3rd Division attacks Devil's Wood. The British made immense gains in the first two days, which was almost unheard of on the Western Front in World War I.