This book explores the complexities arising at the intersection of international law, state sovereignty, and global commerce. The core focus is on how international arbitration can be employed to resolve disputes stemming from the national security screening of foreign direct investment (FDI). The flow of FDI has been integral to global economic development, yet it has increasingly attracted scrutiny from national governments. This scrutiny has intensified due to geopolitical tensions and concerns over the control of critical infrastructure and sensitive technologies. As states aim to balance the economic benefits of FDI with the need to protect national security, conflicts between state actions and international investment agreements have grown more complex. International arbitration, particularly through investor&state dispute settlement (ISDS), represents a crucial forum for resolving these disputes. The book addresses the challenge of upholding international treaties while respecting the legitimate security concerns of states. It provides a detailed examination of how ISDS mechanisms can address these disputes, the legal principles involved, and the broader implications for international law and global investment governance. The study contributes to the ongoing discourse on harmonizing national security needs with the standards of protection promised under international investment law. It critically analyzes the role of arbitration in resolving conflicts arising from national security screenings, offering insights into how arbitral tribunals balance state sovereignty with investor protection. Additionally, it explores potential improvements to the arbitration process to enhance its fairness and efficiency in handling these high-stakes disputes.