Sanction pressure can drive a patron state to abandon its proxy kin

Evidence

Spurred by personal antagonism, the conflict between President Milosevic and Bosnian Serb leader Radovan Karadzic, in contrast, became intense and public. In August 1994 Karadzic rejected the peace plan that had been approved by Milosevic. The Serbian government, anxious to bring sanctions to an end, announced that it was cutting off all trade with the Bosnian Serbs except for food and medicine. — Samuel P. Huntington, The Clash of Civilizations and the…, 822