The European Union and the United States pursue four broad foreign policy objectives in their relations with Serbia: contain Russia, contain China, normalise Serbia-Kosovo relations, and protect the sovereignty of Bosnia and Herzegovina. However, for many years now they have achieved little success on any of these matters. Several reasons explain this, some lying within Serbia and some within Western capitals. EU and US policymakers could change this dynamic, but it appears unlikely they will do so.
How to kill four birds with one stone: The West’s foreign policy challenge in Serbia – European Council on Foreign Relations (ecfr.eu)