Whether a defendant can be convicted of conspiring to aid and abet a crime when the underlying crime is never completed?

QUESTIONS PRESENTED 1. Whether a defendant can be convicted of conspiring to aid and abet a crime when the underlying crime is never completed? 2. Whether, to conspire to aid and abet a crime of international flight from prosecution, a defendant needs specific knowledge that he is helping someone flee internationally, or whether it is sufficient for the defendant to know he is helping someone generally flee prosecution? pretix