In recent years, China, the US, and the EU and its Member States have either promulgated new national laws and regulations or drastically revised existing ones to exert more rigorous government control over inward foreign direct investment (FDI). Such government control pertains to the establishment of an ex-ante review regime of FDI in the host state in sectors that are considered as ‘sensitive’ or ‘strategic’, with an aim to mitigate the security-related implications. This book conducts a systematic and up-to-date comparative study of the national security review regimes of China, the US, and the EU, using Germany as an exampling Member State. It answers a central research question of how domestic law should be formulated to adequately protect national security of the host state whilst posing minimum negative impacts to the free flow of cross-border investment. In addition to analyzing the latest development of the national security review regimes in aforementioned jurisdictions and identifying their commonalities and disparities, this book establishes a normative framework regarding the design of a national security review regime in general and proposes specific legislative recommendations to further clarify the law. This book will be of interest to scholars in the field of international and comparative investment law, investors who seek better compliance programs in the host state, and policymakers who aim for high-quality regulation on foreign investment.