This thesis research concerns the effects of China’s Belt-and-Road initiative (BRI) on the non-European Union (EU) states in the Western Balkan region. The BRI is a large infrastructure project launched in 2014, and its motives have been the subject of international debate. Specifically, it has been considered as a means for China to expand its political and economic influence outside its borders. This research analyses to what extent the BRI has been a successful tool in influencing the foreign policy of two states in the Western Balkan: Serbia and Montenegro. Specifically, whether these states’ foreign policy has shifted to align with Chinese preferences, or whether they are more likely to follow Western, specifically EU, standards in conducting their foreign policy. This research utilizes International Relations (IR) theory to argue the motivations of Serbia and Montenegro to shift their foreign policy in favour of China. Specifically, this question is placed within the debate about power and state behaviour between two leading schools of theory in IR: Liberalism and realism. For each theory, a sub theory has been selected, neorealism and liberal institutionalism, to establish a proposition and indicators that could explain the findings of the case studies of Serbia and Montenegro. The analysis of the data shows that the two case studies have varying results that could each be best interpreted through a different theory. The Serbian case study best aligns with the neorealist proposition, whereas the Montenegrin case study is better explained by the proposition of liberal institutionalism. Therefore, this thesis concludes that the influence from the Chinese expansion of the BRI in this region is varying, and determined by a range of internal and external factors, that China itself does not control.