Andreas Wimmer’s research assumes a long term historical and globally comparative perspective. It asks how states are built and nations formed, how ethno-racial boundaries and hierarchies form or dissolve in the process, and when these inequalities will lead to armed conflict and war. His most recent book is Nation Building. Why Some Countries Come Together While Others Fall Apart (Princeton 2018). He teaches sociology at Columbia University.
You can read more about Andreas' research and background here: https://www.awimmer.com/