As far as I know, no responding party ever invoked GATT Article XX as a defense to a claim of violation of the TBT Agreement (although it would have been fun if they had), but given the various statements the Appellate Body has made recently on the interpretation of both the GATT and the TBT Agreement, it is hard to imagine such a defense would be available today.
By contrast, take a look at what the TPP TBT chapter does with this issue. First off, it says that some of the WTO's TBT obligations are incorporated into the TPP (with an important caveat in paragraph 2):
Article 8.4: Incorporation of Certain Provisions of the TBT Agreement
1. The following provisions of the TBT Agreement are hereby incorporated into and made part of this Agreement, mutatis mutandis: (a) Articles 2.1, 2.2, 2.4, 2.5, 2.9, 2.10, 2.11, 2.12; (b) Articles 5.1, 5.2, 5.3, 5.4, 5.6, 5.7, 5.8, 5.9; and (c) Paragraphs D, E and F of Annex 3.
2. No Party shall have recourse to dispute settlement under Chapter 28 (Dispute Settlement) for a dispute that exclusively alleges violation of the provisions of the TBT Agreement incorporated into paragraph 1 of this Article.
Then look at what happens in the TPP's Exceptions and General Provisions chapter:
Article 29.1: General Exceptions
1. For the purposes of Chapter 2 (National Treatment and Market Access for Goods), Chapter 3 (Rules of Origin and Origin Procedures), Chapter 4 (Textiles and Apparel), Chapter 5 (Customs Administration and Trade Facilitation), Chapter 7 (Sanitary and Phytosanitary Measures), Chapter 8 (Technical Barriers to Trade) and Chapter 17 (State-Owned Enterprises and Designated Monopolies), Article XX of GATT 1994 and its interpretative notes are incorporated into and made part of this Agreement, mutatis mutandis.
So for a complaint brought under the TPP's TBT chapter based on WTO TBT obligations, it seems as though the GATT Article XX exceptions could be used as a defense.
It's kind of hard to know what to make of this. In practical terms, it may just mean that no one would make claims based on the WTO TBT Agreement in a TPP complaint. In terms of policy, and what the drafters intended, can we infer any sort of shift in thinking about the GATT Article III/XX/TBT Agreement relationship?
