論WTO爭端與投資仲裁之平行訴訟調和

Abstract

本文探討「世界貿易組織」(World Trade Organization，以下簡稱WTO) 爭端解決機制 (Dispute Settlement Mechanism) 與「投資人─國家投資爭端解決」(Investor-State Dispute Settlement，以下簡稱ISDS) 下的投資仲裁之平行 (parallel) 訴訟現象與調和方式。近來，投資仲裁面臨許多爭議，例如投資人提訴權造成其與母國及地主國之救濟權不平等、影響地主國規制權等問題。然而，在此背景下， WTO爭端與投資仲裁平行訴訟現象及其衍生問題，往往被忽略。兩種機制之平行訴訟現象源於「國際法碎裂化」(fragmentation of international law) 的情形。投資人透過投資條約下的ISDS，對地主國提起投資仲裁，同時投資人母國或其他國家針對相關爭端，對地主國在WTO提起爭端解決程序，而形成平行訴訟現象。兩者間的平行訴訟，可能對國際法體系、地主國及對WTO爭端解決機制與投資仲裁庭產生之問題，例如場域選擇 (forum-shopping 或forum-choosing)、訴訟經濟 (judicial economy)、衝突法理 (conflicting jurisprudence) 或規範衝突 (conflict of norms) 等。這些問題可能影響國際法穩定性、可預測性與安定性，凸顯管理平行訴訟程序之必要性。因此，本文將針對兩種機制之平行訴訟現象以及調和方式等兩方面進行研究。在平行訴訟現象方面，本文從國際法碎裂化理論檢視兩種機制之平行訴訟及其衍生問題。此外，近年來亦產生四件WTO爭端與投資仲裁平行訴訟的案例，本文亦將一一檢視，試圖從實務經驗觀察平行訴訟現象，並歸納可行之調和方式。在平行訴訟調和方式方面，本文區分國際法原則與條約條款等兩部分，進行調和方式研究：第一，歸納現行適用於WTO爭端與投資仲裁之平行訴訟調和方式，包括條約解釋與一般法律原則之參考與適用等。第二，當前投資條約及國際社會推動之投資法典範轉移 (Paradigm Shift) 與改革倡議中，部分內容有助於調和平行訴訟之問題，前者如場域選擇條款；後者如多邊投資架構 (Multilateral Framework for Investment，以下簡稱MFI) 或例外條款 (subject matter exclusion or carve-outs) 等改革倡議及國際法原則法典化，本文亦將一併討論。

With the rapid development of international investment arbitration nowadays, challenges and controversies facing such a dispute settlement method can be conspicuously observed in literature. However, against the backdrop of such development, issues over parallel proceedings in WTO Dispute Settlement and investment arbitral tribunals remain largely unraised. Parallel proceedings emanate from “fragmentation of international law.” Parallel proceedings arise when investors bring claims against host countries under Investor-State Dispute Settlement (ISDS) conferred by international investment treaties while home countries pursue related cases through the WTO Dispute Settlement. To date, there existed four relevant cases of parallel proceedings between WTO Dispute Settlement and arbitral tribunals, which gives insights to how trade and investment regimes interact, and provides us practical guidance on how they tackle problems of parallel proceedings. Parallel proceedings in WTO Dispute Settlement and investment arbitral tribunals produce enormous number of legal issues and ramifications, including forum-shopping, judicial economy, conflicting jurisprudence, conflict of norms, together with the international legal system as a whole. The thesis consequently argues that those consequences highlight the need to seek methods to better coordinate related proceedings between the WTO and investment arbitral tribunals. As a result, the thesis aims to examine the phenomenon and coordination approaches of parallel proceedings in WTO Dispute Settlement and international arbitral tribunals. The coordination techniques will be addressed in two aspects. Firstly, the thesis explores the feasibilities of existing international norms and rules to regulate related proceedings, by means of treaty interpretation and applicability of sources of law, general principles of law in particular. Secondly, some of the current investment treaties, ongoing paradigm shift and reforms efforts within the investment regime also inform progress ways to manage related proceedings. Lastly, the thesis suggests that among general principles of law, principle of comity, good faith, estoppel as well as abuse of rights may help with coordination of related proceedings. In terms of establishing of proceeding regulating clauses in treaties, subject matter exclusion (carve-outs) provisions, codification of existing international rules, along with explicit conflict clauses provide potential for avoiding parallel proceedings. Considering each coordination technique comes with their own practical restraints when applied to different circumstances and setting of cases, the way to manage parallel proceedings between these two mechanisms remains a fertile ground for future study.