This is from the Tuna 21.5 WTO panel report:
7.466. Before concluding, we note that in its second written submission, Mexico argues that what it considers to be the United States' unilateral action in designing and applying the dolphin-safe labelling conditions and requirements of the amended tuna measure provides further support its claim that the measure is inconsistent with Article I:1 of the GATT 1994. Specifically, according to Mexico, the amended tuna measure's unilateral dolphin-safe regime has the intentional effect of exerting pressure on Mexico to change its tuna fishing practices, even though these practices are already fully compliant with the highly successful AIDCP dolphin-safe labelling regime, as agreed through multinational negotiations between the United States, Mexico, and the other members of the IATTC. Mexico argues that to the extent that Mexico refuses to acquiesce to the unilateral extraterritorial pressure imposed by the United States, the vast majority of its tuna products are denied the advantage of access to the dolphin-safe label in the US market even while they are entirely qualified for the AIDCP dolphin-safe label elsewhere.682
7.467. In response, the United States advanced three arguments. First, the United States argues that the DSB recommendations and rulings did not find that the detrimental impact caused by the US measure was a factor of "unilateral" application and, thus, it is unclear what finding Mexico asks the Panel to make or what the proposed factual basis would be. Second, according to the United States, the argument lacks merit because measures of Members are, by definition, unilateral, and the Appellate Body found in the original proceedings that the objective of the tuna measure is not to "coerce" Mexico. Finally, the United States asserts that Mexico's argument ignores that setting on dolphins, which under the AIDCP is qualified to catch dolphin-safe tuna, harms dolphins even if no dolphin is observed killed or seriously injured in a particular set, and that consequently the AIDCP regime does not meet the United States' chosen level of protection with respect to dolphin protection.683
7.468. The Panel does not need to decide on this point, since it has already found for different reasons that the amended tuna measure is inconsistent with Article I:1.
Governments still make these "unilateralism"-type arguments, but I'm not sure you can win one anymore, except perhaps in the most extreme circumstances. Many years ago, there were some rulings that were favorable to this argument, but I feel like it has fallen out of favor.
