External dimensions of the 2006 Serbian Constitution serve predominately to re-confirm the state sovereignty over Kosovo. After re-declaring that Kosovo is a Serbian autonomous province, the constitutional Preamble creates enforceable rules for all state officials to uphold and protect the state interests of Serbia in Kosovo in all internal and foreign policy relations. At root, these rules support counter-recognition strategies, including the Kosovo derecognition campaign, promoted by Serbia since 2013, when the International Court of Justice ruled that Kosovo's Declaration of independence was not contrary to international law. According to available data, so far, 16 states have derecognized Kosovo. Based on Kosovo's example, this presentation will trace constitutional and international law aspects of derecognition of states, a phenomenon widely untheorized in law, especially when it comes to state derecognition in the context of unilateral secession.