Merriam-Webster Collegiate Dictionary - balkanize

 transitive verb  (-ized; -izing)  Usage: often capitalized  Etymology: Balkan Peninsula  Date: 1919  1. to break up (as a region or group) into smaller and often hostile units  2. divide, compartmentalize now pop culture has been ~d; it is full of niches, with different groups watching and playing their own things — Richard Corliss  • balkanization noun, often capitalized BALKANS  also Balkan States  geographical name the countries occupying the Balkan Peninsula; Slovenia, Croatia, Bosnia and Herzegovina, Macedonia, Serbia and Montenegro, Romania, Bulgaria, Albania, Greece, & Turkey in Europe