Self-determination has turned out to be an ambiguous moral principle. Woodrow Wilson thought it would solve problems in central Europe in 1919, but it created as many as it solved. Adolf Hitler used the principle to undermine fragile states in the 1930's. Today, with less than 10% of the world's states being homogeneous, treating self-determination as a primary moral principle could have disastrous consequences in many regions.
Nye, Jr., Joseph S. "The Dark Side of Self-Determination." Daily News, January 11, 2009.