INS v. Chadha, 462 U.S. 919, 103 S.Ct. 2764, 77 L.Ed.2d 317 (1983).
To these broad principles underlying the task of judicial interpretation, two further points emerge more directly bearing on this case. First, although extrinsic sources vary widely in their reliability (and thus are not susceptible to wholesale classification as to their usefulness), when, as here, legislation arises in response to a need voiced by the Executive Branch, interpretive aid may ofttimes be found in those voices providing the impetus to legislation. See, e.g., United States v. Rock Island Motor Transit Co., 340 U.S. 419 n. 9, 71 S.Ct. 382 n. 9, 95 L.Ed. 391 (1951); see also International Brotherhood of Teamsters v. ICC, 801 F.2d 1423, 1428 & n. 4 (D.C.Cir.1986), reh’g granted, 818 F.2d 87 (D.C.Cir.1987). This is especially so when, as is also true here, the Executive takes an active role in drafting the legislation and presenting it to Congress. See, e.g., United States v. Vogel Fertilizer Co., 455 U.S. 16, 31-32, 102 S.Ct. 821, 830-31, 70 L.Ed.2d 792 (1982); Miller v. Youakim, 440 U.S. 125, 144, 99 S.Ct. 957, 968, 59 L.Ed.2d 194 (1979). In this situation, the views and interpretations of these Executive Branch actors provide a context for what may be, in some respects, a legislative response to an executive request.
Second, while courts recognize the inevitability and, in certain contexts, the desirability of legislation that leaves some details to be resolved as the statute is applied, there are limits. Those limits are most graphic in cases involving criminal sanctions. This is elementary to our law. In the criminal context, courts have traditionally required greater clarity in draftsmanship than in civil contexts, commensurate with the bedrock principle that in a free country citizens who are potentially subject to criminal sanctions should have clear notice of the behavior that may cause sanctions to be visited upon them. See, e.g., Dowling v. United States, 473 U.S. 207, 218, 228-29, 105 S.Ct. 3127, 3134, 3139-40, 87 L.Ed.2d 152 (1985).
That is to say, the law of crimes must be clear. There is less room in a statute’s
regime for flexibility, a characteristic so familiar to us on this court in the interpretation of statutes entrusted to agencies for administration. We are, in short, far outside Chevron territory here. See Chevron U.S.A. Inc. v. Natural Resources Defense Council, 467 U.S. 837, 842-45, 104 S.Ct. 2778, 2781-83, 81 L.Ed.2d 694 (1984); see also INS v. Cardoza-Fonseca, — U.S. -, 107 S.Ct. 1207, 1220-22, 94 L.Ed.2d 434 (1987). Related to that obvious point is the fact that, as a practical matter, the clarity demanded in the criminal law can prove to be more difficult to achieve in prescribing mala prohibita than in addressing the traditional mala in se. In the former, Congress is not legislating against the rich tapestry of the common law, a backdrop which may help invest enactments with meaning afforded by history. See, e.g., Standefer v. United States, 447 U.S. 10, 19, 100 S.Ct. 1999, 2005, 64 L.Ed.2d 689 (1980). Instead, Congress is venturing into less well-charted seas, where the frame of reference necessary to understanding may be more difficult to fix both by courts and, more fundamentally, by those who are subject to the law’s strictures. Cf. Viereck, 318 U.S. at 241-42, 63 S.Ct. at 563-64.
With these broad principles in mind, we turn to the statutory provisions at the heart of the controversy before us.
B
The first (and most basic) step on any interpretive path is the language of the statute itself. See, e.g., United States v. Hohri, — U.S.-, 107 S.Ct. 2246, 2250, 96 L.Ed.2d 51 (1987); Landreth Timber Co. v. Landreth, 471 U.S. 681, 685, 105 S.Ct. 2297, 2301-02, 85 L.Ed.2d 692 (1985); Consumer Products Safety Comm’n v. GTE Sylvania, Inc., 447 U.S. 102, 108, 100 S.Ct. 2051, 2056, 64 L.Ed.2d 766 (1980); Overseas Education Association v. FLRA, 824 F.2d 61, 64 (D.C.Cir.1987). We therefore begin by setting out the precise terminology of one of the two relevant statutory provisions, section 618(e) of FARA:
Failure to file any such registration statement or supplements thereto as is