Abstract

The enforcement of ICSID arbitral awards has long rested on the assumption that treaty-based recognition ensures effective compliance. This article examines whether that assumption remains tenable in light of the UK Supreme Court's decision in The Kingdom of Spain v Infrastructure Services Luxembourg SARL , which held that a State's consent to the ICSID Convention constitutes a clear submission to jurisdiction under Section 2(2) of the UK State Immunity Act 1978, thereby excluding sovereign immunity at the recognition stage of enforcement.

Building on this judgment, the article interrogates the interaction between Articles 53-55 of the ICSID Convention  and domestic immunity regimes, including the United States Foreign Sovereign Immunities Act. It argues that while ICSID awards are formally binding and must be recognised by contracting States, the Convention leaves unresolved the extent to which sovereign immunity constrains enforcement in domestic legal systems.

Through a comparative analysis of the United Kingdom, the United States, and selected common law jurisdictions, the article contends that ICSID enforcement has evolved into a structurally bifurcated regime: recognition is governed by treaty obligation, while execution remains subject to domestic immunity law. This produces a fragmentation in enforcement outcomes whereby investors may obtain recognition of awards without meaningful recovery against sovereign assets. 

This article concludes that the UK Supreme Court's decision confirms the effectiveness of Article 54 of the ICSID Convention, while highlighting the enforcement architecture, in which Article 55 preserves immunity from execution. The result is an "hollow victory" in ICSID enforcement, revealing a deeper decoupling between legal enforceability and practical recovery.