[en] This article examines selected system-level variables. Its premise is that a better understanding of how and why scholars may, or may not, choose an international orientation in their career requires taking into account factors beyond personal preferences or constraints. We suggest that characteristics of national systems shape prospects and strategies of internationalisation and look at two broadly defined variables : resource availability and career incentives. With respect to the first, we study the absolute level of national resources and their relative importance vies-a-vis those provided by the EU. With respect to the second, we consider the rules and norms governing the progress of academic careers, especially the extent to which international collaboration is significant and necessary for initially attaining a stable academic position and career advancement. We explore these questions through targeted comparison of four national cases, selected to ensure crosscutting variation across the selected variables. A comparison of two relatively low-resource cases (Bulgaria and the Czech Republic) with two relatively high-resource ones (France and Finland) is followed by a comparison with respect to career incentives. This allows to conclude that both factors should be considered as necessary conditions for internationalisation, and to suggest how this hypothesis might be further tested in subsequent research.