Can a criminal conspiracy be established "regardless of whether the crime agreed upon"?

The appellants also contend that they were improperly indicted for, and ultimately convicted of, conspiring to possess cocaine. They argue that, because the government never had any cocaine to sell, it was legally impossible for the appellants to have committed the underlying offense of possession. We disagree. A criminal conspiracy may be established "regardless of whether the crime agreed upon is actually committed." United States v. Feola, 420 U.S. 671, 694, 95 S.Ct. 1255, 1268, 43 L.Ed.2d 541 (1975). The fact that the government had no cocaine to sell is irrelevant.