For 10 points, name this post-WWI conflict that saw the Red Army's invasion of Western neighbor stopped at the Battle of Warsaw.
King Kong director Merian Cooper was subject to a massive bounty during this war, which saw him imprisoned as a POW after volunteering for one side's air force. The open letter "To All Former Officers, Wherever They May Be" was published during this war by a side desperate to recover its mass-deserted cadre. One side in this conflict allied with the government of Symon Petliura and relied on the cryptography skills of Jan Kowalewski. It featured such units as Jozef Haller's "Blue Army" and Semyon Budyonny's famous 1st (*) Cavalry Army, which was defeated at the Battle of Komarow, history's last great cavalry battle. The Treaty of Riga ended this conflict after the forces of Mikhail Tukhachevsky were surrounded and routed by Jozef Pilsudski at the Miracle at the Vistula," and it is often seen as the westernmost theater of a civil war against the White Army. For 10 points, name this post-WWI conflict that saw the Red Army's invasion of Western neighbor stopped at the Battle of Warsaw.
King Kong director Merian Cooper was subject to a massive bounty during this war, which saw him imprisoned as a POW after volunteering for one side's air force.
Polish-Soviet War [accept Russo-Polish War of 1919-1921, Polish-Bolshevik War, Bolshevik War or the War of 1920; prompt on "Russian Civil War" or equivalent answers]