In 1911, v. Papen worked as a major in the German general staff and in 1913, became military attaché in Mexico and in the USA. After the beginning of war he reported to the Germans on the shipping of war materials from the USA to Europe. V. Papen tried to impede the American war production by economic ways, (the 'Bridgeport Projectile Company'). In December 1915, v. Papen and the marine attaché Boy-Ed were declared as persona non grata by the United States government and both left America.
V. Papen became battalion commander of the 2. Batallion of Reserve Infantry Regiment No. 93 in the 4. Guards Infantry Division. He fought with his battailion at the Vimy Hill and at the Somme. During the Battle of the Somme, v. Papen became 1. Officier in the General Staff (chief of the operation department - Ia) of 4. Guards Infantry Division (October 6, 1916 - June 15, 1917). Subsequently he became Ia of the Army Group v. Falkenhayn and was sent to Palestine. In the spring of 1918 v. Papen was promoted lieutenant colonel and to the chief of general staff of the re-activated 4. Osmanian Army (general Cemal Pascha). The offensive in autumn 1918 by the British general Allenby and the breakdown of the Bulgarian front made Turkey request an armistice. The treaty of armistice were signed on October 30, 1918 in Mondros, and the Germans, including v. Papen, were interned in Moda. V. Papen escaped in December 1918 and arrived back in Germany on January 6, 1918.
Papen, Franz v. Der Wahrheit eine Gasse, Innsbruck: List,1952
Kurt, Gabriel, Die 4. Garde-Infanterie-Division. Der Ruhmesweg einer bewahrten Kampftruppe durch den Weltkrieg, Berlin: Klasing, 1920
Schlachten des Weltkrieges in Einzeldarstellungen. 2nd ed., Vol. 4, Oldenburg: Stalling, 1924
Sievers, Adolf, Reserve-Infanterie-Regiment 93. Geschichte eines Regiments im Weltkriege, Wilster: Schwarck, 1935