In a communication related to the AB's Hormones Suspension decisions, the U.S. says:
3. Accordingly it is clear that the Appellate Body can clarify, but not interpret or amend, any of the covered agreements, including the DSU.
Putting aside "amend," it is not very clear to me what the difference is between "clarify" and "interpret," especially given that DSU Article 3.2 refers to "clarify[ing] the existing provisions of those agreements in accordance with customary rules of interpretation of public international law." (emphasis added) What exactly is "clarifying" under DSU Article 3.2 and how does it relate to "interpreting" under WTO Agreement Aricle IX:2? On this point, take a look at this statement by the AB at para. 161 of U.S. - Stainless Steel (Mexico):
Clarification, as envisaged in Article 3.2 of the DSU, elucidates the scope and meaning of the provisions of the covered agreements in accordance with customary rules of interpretation of public international law.
That definition of "clarification" sounds a lot like the definition of "interpret." From the New Shorter Oxford English Dictionary: "To explain the meaning of." (I don't have the dictionary on me right now to double-check, but that's from an old article I wrote. Here's the same definition from an online dictinonary: http://www.thefreedictionary.com/interpret. That same dictionary defines "clarify" as "To make clear or easier to understand; elucidate.")
I can understand the U.S. concern, but without more guidance in the DSU as to the proper scope of the AB's role, it is very difficult, in my view, for the AB to know just how much "clarifying" it may do before it has crossed over into "interpreting."
