The fortress played a role in World War I. In October, 1914 a significant battle was fought in its vicinity, in which the Russian armies repelled a combined German and Austro-Hungarian offensive. After that battle the defences of the fortress were further improved, and it became even more important as an anchor of the Russian position on the Vistula. However, reverses elsewhere along the front forced the Russians to abandon Ivangorod in August 1915. In 1920, the Dęblin area was the starting point for a Polish offensive that decided the fate of the Battle of Warsaw and the entire Polish–Soviet War. In the years 1918–1939, as part of independent Poland, Dęblin continued to have large military significance. The Dęblin fortress was garrisoned by the 15th Infantry Regiment of the Polish Army, and in the nearby village of Stawy one of the largest ammunition depots of the Polish Army ("Główna Składnica Uzbrojenia nr. 2") was located. In 1927 the famous Polish Air Force academy was officially moved to Dęblin, after its founding in Grudziądz in 1925 (some pilot training has been conducted here since 1920). It continues to function today.