What constitutes a showing of duress less than what constitutes a defense to a crime?

7 "Evidently the Commission had in mind the showing of duress less than what constitutes a defense to a crime; for if the defense were 'complete,' there would have been no crime requiring a sentence.... If the court should conclude that [the defendant] has not carried her burden of proving duress because her evidence of duress is not credible, it is still open to the court to consider whether there was duress that did not amount 'to a complete defense.' " United States v. Johnson, 956 F.2d 894, 898-99 (9th Cir.1992) (citation omitted).