 Complete the following phrase:  Hostilities over the Suwałki Region resumed in summer 1920. When the Polish Army began to retreat during the course of the PolishSoviet War, the Lithuanians moved to secure what they claimed to be their new borders, set by the SovietLithuanian Peace Treaty of July 1920. The Peace Treaty granted Sejny and surrounding area to Lithuania. Poland did not recognize this bilateral treaty. Ensuing tensions heightened until the outbreak of the 