The Umbrella Clause in International Investment Law: Approaches in Arbitral Practice

This article examines the legal nature and practical significance of the umbrella clause within the system of international investment law, focusing on how arbitral practice interprets and applies this mechanism. It addresses the core distinction between treaty-based and contract-based investor claims and considers the legal implications of “internationalising” breaches of investment contracts where relevant provisions are included in bilateral investment treaties. The study outlines the principal interpretative models—restrictive and expansive—and identifies the factors that shape arbitral determinations on jurisdiction and the admissibility of disputes. Particular emphasis is placed on the need for legal certainty in treaty drafting, coherence between dispute settlement arrangements, and an appropriate balance between public regulatory interests and private investor protection.