In 15 ABY, following the Retribution of Coruscant the Caspian Democratic Union was forced to sign the CDU Nonaggression Treaty with the Galactic Empire, which established the Union's neutrality in the civil war, pledging to deny military support and accommodation to both sides. Though diplomatic relations were almost immediately threatened by the arrest of a Caspian diplomat on charges of aiding sedition, the treaty remained in force.