In 1929, the Polish government nationalized the forestry industry, and many of the Jews of Bielica lost their livelihood. The town entered a period of economic decline. Nevertheless, Jewish political and cultural life continued to flourish: the town was home to chapters of Hechalutz and of the leftist Zionist Dror party. The 4-year Horev religious school, which was sponsored by the Polish state, was a source of pride for the local Jews.
In September 1939, World War II broke out, and Bielica was occupied by the Soviets. As part of the Sovietization program, all the businesses in the town were nationalized, and the new authorities suppressed all forms of non-Communist political and cultural activity. The Horev school was secularized, and the language of instruction in it was changed to Yiddish.
In June 1941, the Soviet-German War began. On June 28, the Germans occupied Bielica. As the Wehrmacht was entering the town, someone shot at the soldiers from the fire tower. The Germans took 18 hostages, both Jewish and non-Jewish, and carried out a shooting; seven people were killed, and many others wounded. Furthermore, the Germans set fire to the Jewish quarter, including the synagogue and the Horev school. In the following days, the occupiers issued anti-Jewish decrees and imposed forced labor on Jews. In July 1941, the Germans picked 36 Jewish men (including the town rabbi, a doctor, and a pharmacist), imprisoned them in the gmina (town administration) building, and then shot them near the Eastern Orthodox Church building.
In November 1941, the Germans transferred 600 Bielica Jews to the ghettos of Lida, Zdzięcioł, and Szczuczyn, where they shared the fate of the other inmates of those ghettos.