Wrapping up the series of posts on GATT Article XX, let me ask this: Can GATT Article XX be a defense to an Article XXIII:1(b) non-violation claim?
The "exception" language in Article XX is pretty broad: "nothing in this Agreement shall be construed to prevent the adoption or enforcement by any Member of measures ... ." This language does not refer to violations of specific obligations, or to obligations in general; it just says that "nothing in this Agreement" shall prevent certain measures. Presumably, for the purposes of Article XX, a finding that a measure is in violation of a particular GATT provision has the effect of "preventing" that measure. Of course, in reality, a finding of violation does not "prevent" anything. All that WTO rules can do is authorize retaliation, which could induce the Member to modify or repeal it, but may not always do so. The assumption seems to be that findings of violation do, in some sense, "prevent" such measures, and thus Article XX can be used to justify measures that would otherwise violate the rules.
Similarly, a finding of non-violation nullification or impairment could also be said to "prevent" measures. While the remedy for such claims is weaker than for violation claims (see DSU Article 26.1), a mechanism for complaining about such measures does exist. And, furthermore, at the time the GATT was drafted, the distinction between the two kinds of claims (violation and non-violation) was not so pronounced.
On the other hand, is GATT Article XXIII an "obligation" of the sort people have in mind here? Can the "general exceptions" of Article XX be applied to it? Or do these exceptions only apply to the "substantive" obligations?
