the label is balkanization

• WASHINGTON - Satellite images taken at night show heavily Sunni Arab neighborhoods of Baghdad began emptying before a U.S. troop surge in 2007, graphic evidence of ethnic cleansing that preceded a drop in violence, according to a report published on Friday.
• The images support the view of international refugee organizations and Iraq experts that a major population shift was a key factor in the decline in sectarian violence, particularly in the Iraqi capital, the epicenter of the bloodletting in which hundreds of thousands were killed.("Satellite images show ethnic cleanout in Iraq," By Maggie Fox, Health and Science Editor, Reuters, Fri Sep 19, 2008)