Focusing on cooperative exchanges between Czechoslovakia and Poland in the 1960s and 70s, this collection explores international science collaborations during the Cold War. During the era of real socialism, the states of Central and Eastern Europe were caught between the "East" and the "West." As members of the Eastern Bloc they had to adhere to Moscow centrism, yet partial autonomy in scientific internationalism and longstanding Western-oriented traditions created space for exceptions. The Contributors to this volume provide a nuanced understanding of socialist hierarchies and the knowledge transfers they facilitated, challenging the perception that socialist scholars acted solely according to rigid, reciprocal plans.