The article considers foreign scientific literature devoted to exogenous factors (regarding the interaction of clusters with global innovation systems) that limit the interaction of firms with global markets and value chains. The following research methods were applied in the article: analysis of modern scientific literature by foreign authors, focused on the aspect of internationalization of cluster small and medium-sized businesses. The purpose of this study is to consider the importance of the internationalization of clusters in a theoretical aspect. Analyzed 52 scientific articles in the field of internationalization of cluster enterprises of small and medium-sized businesses. The study characterizes the positive and negative impact of internationalization on clusters. The positive aspects of inter-cluster cooperation in the international space are highlighted. The factors due to which the internationalization of the cluster can be achieved are determined. The conclusion is made about the potential positive and negative impact of internationalization on clusters. The positive impacts include access to knowledge through cluster networks/relationships, observation/imitation, inter-firm labor mobility, technology diffusion, higher likelihood of being "found" by international counterparties, etc.); to a negative impact – local congestion, intense local competition, distrust between cluster members, excessive dependence on specific resources of the region, "poaching" of workers by other cluster firms, loss of technological advantage due to imitation/"theft" of technologies, etc.