7.1 Introduction

1. Chapter 6 considered the place of third person submissions in arbitral proceedings subject to the UNCITRAL Rules on Transparency in Treaty-based Investor-State Arbitration (the Rules). As will be noted, this chapter is also concerned with submissions made by a third party to the relevant investment arbitration proceedings. However, it deals specifically with submissions made to an arbitral tribunal by a ‘nondisputing party to the treaty’, that is, by an entity that is not a party to the relevant arbitral proceedings, but is a Party to the treaty on investment pursuant to which those proceedings are brought. This chapter will begin by outlining the background and purpose of Article 5, as well as the history of non-disputing Party submissions in State practice and case law, before analysing the text of Article 5 of the Rules and addressing a number of the key issues it raises.

7.2 Background and purpose

2. Article 5 is entitled ‘Submission by a non-disputing Party to the treaty’. As noted, its purpose is to provide rules to govern submissions made to an arbitral tribunal by a Party to the relevant investment treaty that is not a party to the arbitration proceedings brought thereunder. Given that a non-disputing Party is, by definition, not a party to the relevant investment arbitration proceedings, Article 5 submissions may be considered to be a form of third person, or amicus curiae, intervention, as the UNCITRAL's Working Group II (Arbitration and Conciliation) (WG) on the Rules acknowledged. Indeed, in its original form, Article 5 was one paragraph in what is now Article 4, which addresses third person submissions more generally. Ultimately, non-disputing Party submissions were addressed separately in the Rules, with Article 4(1) expressly excluding non-disputing Parties from its scope. As will be discussed in further detail below, there are important reasons for keeping the two distinct, especially insofar as the views of a non-disputing Party on questions of treaty interpretation are of particular legal significance for the proper interpretation of that treaty. The involvement of a nondisputing Party may also raise concerns of prejudice of a particular kind to the parties to the arbitral proceedings, namely the risk that a State of nationality engages in the diplomatic protection of one of its investors.