This contribution sets out to clarify the determinants and modalities by which Russian companies played a part in structuring the energy complex of central and eastern European countries. In so doing we seek to supplement state-centred analysis of realist inspiration. The Soviet legacy explains both the incentive for Russian companies to develop operations in downstream oil and gas in these countries and why, given the vulnerability of national energy systems, target countries tend to see such developments as a threat to their security. In this respect the mid-2000s may be seen as a turning point, with the downstream growth strategies of Russian energy suppliers increasingly called into question.