What is the impact on a defendant's sentence of his refusal to cooperate with the government?

This is not the first time that we have examined the question of the impact on a defendant's sentence of his refusal to cooperate. In United States v. Stratton, 820 F.2d 562 (2d Cir. 1987), the district court imposed a consecutive ten-year sentence on a defendant, instead of making it concurrent to his prior fifteen-year sentence, to "convince [him] that cooperation with the government is in [his] best interest." Id.at 563 (quoting the district court at sentencing). We stated then that although a sentencing court could consider the failure to cooperate, seeRoberts v. United States, 445 U.S. 552, 557-58 (1980), there was an important "distinction between increasing the severity of a sentence for a defendant's failure to cooperate and refusing to grant leniency." 820 F.2d at 564. Examining the district court's remarks at sentencing, we held that the district court in that case had improperly enhanced the defendant's sentence. See id.