Rubuta ci gaba don wannan sakin layi - Abin takaici ga Sibert, lokacin da Amurka ta shiga yakin duniya na a watan Afrilu 1917, Brigadier Janar Sibert na ɗaya daga cikin manyan jami'an sojan sama da ke aiki. An ba shi izini a matsayin babban janar kuma an tura shi tare da rukunin farko na rundunar sojan Amurka (AEF) wanda ya kafa sashen sojan kasa na 1 (wanda ake kira "The Big Red One") sau ɗaya a Faransa. Kwamandan AEF, Janar John Joseph Pershing, wani jami'in soja mai tsawo wanda ya shahara saboda ayyukansa a San Juan Hill
a cikin Yakin Mutanen Espanya-Amurka, kuma kwanan nan da ke kula da yakin da Pancho Villa, ya kasance a kan manyan jami'ai (shi da kansa kwanan nan ya ci gaba da matsayinsa) don haka an sanya Sibert a matsayin shugaban na 1st Infantry Division.