Many of those who take a different position point to the ‘except clause’ in Article 4(a) 986 and to the desideratum of ‘uniform’ CISG application, 987 but I think that involves too much of a stretch:

‘A[n] example of an unduly rigid view of the [CISG] uniformity principle leading to unjustified conclusions involves the interpretation of the rule in Article 4 that questions of contractual ‘validity’ are beyond the scope of the Convention, and are governed by applicable national law. To counteract this threat [to uniform CISG application ... Peter Schlechtriem] argued that the reach of the validity exception should be limited by confining the term ‘validity’ to issues that are almost universally treated as a matter of validity in the various national legal systems. The drafters’ purpose in creating the ‘validity’ exception, however, was to preserve the applicability of national rules deemed important enough by individual states that the rules were not, under the state's domestic law, subject to contrary agreement of the parties. ... Nothing in the uniformity principle of Article 7(1) justifies such an attempt to undermine the purposes behind the validity exception.’ 988

To take this a step further, let’s assume, for the sake of argument, that the domestic unconscionability rule in UCC § 2-302 was as ‘expansive’ as the General Clause in § 36 of the Danish Contracts Act, so that the UCC rule (like the Danish rule) also authorized contract adjustment by reason of supervening events. Would American CISG scholars then argue that (my hypothetical version of) UCC § 2-302 was not a rule of validity, and that the United States, by ratifying the CISG, traded that ‘supervening’ part of § 2-302 away in exchange for ‘uniform’ application of CISG Article 79? 989

I dare not answer that question, but I do argue that the General Clause in the Danish Contracts Act remains a viable validity rule in the international context – a rule not displaced by CISG Article 79, not ‘traded away’ when Denmark ratified the CISG.

Lastly, and mindful of the Festschrift in which the present paper appears, I find it appropriate to translate an excerpt from The Law of Obliga-