外國投資保護與東道國社會利益的衝突紓解：比例原則作為必要工具的理論證成

Alleviating the Conflict between Foreign Investment Protection and Host State Social Interests: The Theoretical Justification of the Principle of Proportionality as a Necessary Tool

外國投資者的投資者權益與東道國社會利益之間的衝突一直是國際投資仲裁的爭議核心。如何對其進行紓解也成為了不可規避的話題。一方面，由於投資條約中規制利益衝突的例外條款表述大多較為模糊，無法給仲裁庭提供實質指導；另一方面，非投資利益的具體內涵需要仲裁庭通過參考一般法律原則進行解釋。但因為國際法規範的碎片化與無序性，仲裁庭同樣無法據其作出明確的認定。在這種情形下，比例原則作為必要的理論工具可以為仲裁庭提供方法支持。比例原則是國際法中的一般法律原則，其適用具有國際法淵源層面的合法性；其價值統合以及優化平衡的功能與解決法律原則衝突的內在邏輯完美契合，證明了其適用的合理性；二者共同證成其作為紓解利益衝突困境理論工具的必要性。適用過程中存在的審查標準等問題，可以通過“司法尊讓”理念的引入得以最大程度的緩解。

Although the principle of proportionality is widely cited in resolving disputes, the deeper conflicts between the protection of investor rights and the public interests of host states remain unresolved. In many cases, this is not only due to the ambiguities inherent in the rules of BITS, but also due to the piecemeal and inconsistent application of general principles of law. This fragmentation creates further conflict, as arbitral tribunals struggle to find a consistent framework for balancing competing interests. By examining the works of legal scholars such as Ronald Dworkin and Robert Alexy, it becomes clear that even when legal principles conflict in certain situations, they can still coexist. Dworkin's theory of ''law as integrity'' suggests that law is best understood as a coherent system of principles that must be interpreted in a way that gives the best possible fit to the existing body of law. This view is echoed in Alexy's theory of constitutional lights, which emphasizes the importance of balancing conflicting principles to achieve an optimal outcome. Both scholars recognize that conflicts between legal principles are inevitable, but they argue that such conflicts can be reconciled through careful and thoughtful interpretation that seeks to maximize justice and fairness. In the context of international arbitration, this theoretical framework aligns with the mechanism of the proportionality principle. Proportionality operates through a three-step test: suitability, necessity, and proportionality in the strict sense. The suitability and necessity steps involve comparing the benefits and burdens of a measure in factual terms, determining whether it effectively achieves its purpose and whether a less restrictive alternative could be used. The final step, proportionality in the strict sense, requires a legal and normative balancing of interests, weighing the importance of the measure against the rights it infringes upon. This step is crucial for finding a solution that accommodates multiple interests, including both investor protection and the public policy goals of the host state. To ensure the proper application of proportionality, arbitral tribunals should adopt a ''judicial deference'' approach, taking into account the specific social and national characteristics of the host state. This would allow for more context-sensitive decisions that are better suited to the realities on the ground. Judicial deference emphasizes respect for the host state's regulatory autonomy, recognizing that states are in the best position to assess the needs of their societies. By incorporating the local context into their decision-making, arbitral tribunals can arrive at more appropriate and balanced conclusions that respect both the rights of investors and the regulatory interests of host states. However, the proportionality principle is not without its challenges and one of the major difficulties lies in the quantification of competing interests. This process of balancing is inherently subjective, and there is no one-size-fits-all solution. Yet, despite these limitations, the proportionality principle remains a valuable tool for resolving disputes in international arbitration. To conclude, proportionality offers a structured and principled approach that helps arbitral tribunals navigate the complexities of competing interests in a fair and reasoned manner.