What it is: 'Balkanisation' means the imposed division of any territory or large group of people into small states or smaller groups who are hostile to each other.
What it means: 'Balkans' is Turkish for 'mountains' and 'The Balkans' is the name given to a group of countries in south-east Europe: Albania, Bosnia Hercegovina, Bulgaria, Croatia, Greece, Macedonia, Romania, Serbia and Montenegro, and Slovenia. A number of different ethnic groups live across the region. The mainly mountainous land means that armed fighters can easily attack, evade, and trick opponents: any armed conflict there is hard to control or stop. At the end of the 19th century and the beginning of the 20th century, western powers divided the Balkans into small separate countries with new, imposed boundaries. This caused conflict between the ethnic groups. According to which country they were now in, members of each group were a powerful majority, or an oppressed minority, or one of several groups roughly the same size. Whatever the case, they found it difficult to set up governments. Balkanisation can quickly create dangerous political and military situations with effects reaching far beyond the 'Balkanised' units themselves. People recognise that Balkanisation is an unwise thing to do, though that hasn't always stopped them. Dividing a country into regions that cut across the fault lines between different groups is asking for trouble, yet it has been done (for example) in a number of former colonies.
Think about it: One underlying problem is how boundaries are imposed in the first place: the power to do it is mostly in the hands of leaders or other countries who may not care about (or even listen to) the opinions, hopes and fears of the people who actually have to live there. Examples of this can be found locally in many places where two or more different groups live or work. What ought to be taken into account (and how) when making boundaries, whether in towns, districts or countries? Could peace across the boundaries depend on how (as well as where) the boundaries are actually marked? Could real peace mean that boundaries are no longer needed?