Answer: The states that are mostly likely to be pulled apart by nationalism are the multinational ones, as very often two or more ethnic groups in the same boundary tend to have tensions between
Explanation: The nationalism represents a feeling of belonging, appreciation, preservation to a particular group, cultural group, and ethnic group. The nationalism can be very good, but also very bad. If it is focused on the culture, its cherishing and preservation, than it is not a problem. A problem occurs when the nationalism becomes extremist, and a group starts to propagate superiority over other ethnic groups, or starts with violence over people of other groups.
sorry if i am wrong