Prods. Co. v. United States, 288 U.S. 294, 318, 53 S.Ct. 350, 77 L.Ed. 796, (1932)). This stems from the fact that “the United States uses a ‘retrospective’ assessment system under which final liability for antidumping and countervailing duties is determined after merchandise is imported.” 19 C.F.R. § 351.212(a). While importers entering merchandise subject to an antidumping duty order are required to make a cash deposit of estimated antidumping duties, this rate is not final where an administrative review is initiated. Accordingly, in cases involving importers’ challenges to the application of new laws based on retro-activity, we have looked at liquidation as the paramount relevant “past event.” See, e.g., Travenol Labs., Inc. v. United States, 118 F.3d 749, 753 (Fed.Cir.1997) (<HOLDING>); see also Syva Co. v. United States, 681
holding no retroactive application holding that liquidation of entries is the triggering or operative event for deciding whether application of a statute or regulation is impermissibly retroactive holding iiriras preclusion of application for relief constitutes a new disability and is impermissibly retroactive holding retroactive application recognizing that the application of a retroactive amendment is discretionary