INFLUENZA VIRUS, THE PLAGUE THAT MAY RETURN
In the spring of 1918, the German army again launched a massive attack on France, in anticipation of successfully concluding the First World War ( 1, 2). Russia's withdrawal from the war enabled Germany to move more than one million experienced men and 3000 guns to the Western front, where Germany then had numerical superiority. The Germans placed thirty-seven infantry divisions there and had almost thirty more in reserve. This was the greatest assault force to date, and in several sectors it outnumbered those of the British and French by a ratio of four to one.
The French were desperate, and the British army had sustained serious losses at the battle of Passchendaele. With her enemies so depleted, Germany's main hope of success depended on an early attack, before additional American forces could arrive.
At first, the Germans made substantial progress, gaining over 1,250 square miles of French soil within four months. By May, the German army reached