Complex sentence: The KGB (Committee for State Security; Russian: Комит́ет Госуд́арственной Безоп́асности; Komitet Gosudarstvennoy Bezopasnosti) crashed a Zionist group meeting, and arrested all the participants, including Borya, who was convicted and sent to a Gulag in Siberia for three years.
Split into simpler sentences: The KGB (Committee for State Security; Russian: Комит́ет Госуд́арственной Безоп́асности; Komitet Gosudarstvennoy Bezopasnosti) crashed a Zionist group meeting. They arrested all the participants, including Borya, who was convicted and sent to a Gulag in Siberia for three years.