This paper examines a key concept in legislation restricting foreign participation in the Russian economy – "control by a foreign investor" over a strategic business entity. Correctly determining the presence or absence of such control is of fundamental importance both for market participants – foreign investors intending to acquire strategic assets, and for authorized bodies applying the law to prevent violations and mitigate the consequences of their violation. Based on an analysis of legal regulations and judicial decisions, practical approaches to understanding "de facto corporate control" by a foreign investor over a strategic entity are formulated.