He left in 1916 when Romania entered World War I; in any case, Mihăescu had not passed any exams during two years of study. Mobilized in autumn 1916, he attended an officers’ school in Botoșani for three months. He saw action at the Battle of Mărășești and in the Muscel area, and was decorated.
He left Romania in 1916 when it entered World War I; however, Mihăescu had not passed any exams during his two years of study. Mobilized in autumn 1916, he attended an officers' school in Botoșani for three months. He participated in the Battle of Mărășești and the Muscel area, receiving a decoration for his service.