Nationalism arouses solidarity and generates identity politics that threaten ethnic and religious minorities. Defining the "we" also defines the "they" — and the latter is inexorably marginalized.
Identity politics carry with them a high risk of sectarian or communal violence. State abuses of authority, and impunity for abusers, often transform grievances into a shared collective identity among victimized minorities, generating defiance, militancy and a cycle of violence.
China's Muslim Uighurs from Xinjiang, and Buddhist Tibetans, are resisting assimilation despite sustained efforts by ethnic Han Chinese. Both groups harbor strong resentments against Han-ification that sometimes erupt into violence — direct action that's quickly suppressed by security officials.