This paper explores how the concept of mitigation in FDI reviews originated, identifies the standards for negotiating or imposing mitigation, and compares the enforcement mechanisms across FDI screening regimes in the United States, France, Germany, and United Kingdom using the United States’ Committee on Foreign Investment in the United States (“CFIUS”) as a model. The paper will explore how changes over time to FDI screening risk mandates impact the effectiveness of mitigation, describe commonly used mitigation methods, and analyze the development of alternative authorities that could impact the authority to mitigate. As shown by the history and development of mitigation methods across these four FDI regimes, mitigation offers regulators a way to balance their competing concerns: on the one hand, an open investment policy and, on the other hand, the need to address weaponized investments in areas critical to domestic national security.