In 1910, Schemua was responsible for nationwide mobilization in the Ministry of War. From 1911 to 1912 he was Chief of the Austro-Hungarian General Staff, the highest position in the hierarchy of the Austro-Hungarian Army. At the beginning of the Balkan Wars of 1912–13 he was appointed commander of the 16th Corps in Dubrovnik and promoted to "Feldmarschalleutnant" (lieutenant field marshal). In 1913 he was promoted to general of the infantry. At the beginning of World War I in 1914, during the Battle of Galicia, he commanded the 2nd Corps, but failed to distinguish himself at the Battle of Komarów. He was replaced by . He was then appointed commander of the defense of Danube from Krems to Pressburg. In 1915 he retired at his own request.