Right. Most nefarious actors just buy most of their stuff retail. Figuring that out, from whom, what was purchased etc. and if it violates some sanctions regime is one of the things the NSA might participate in, handing off the findings to the State Department of the Commerce Department or whoever for action. The action being that participating companies would not be allowed to do business in the U.S. and would be monitored for further sanctions violations in case other U.S. involved companies want to do business with the retail outfit that sold the whiskey. No big deal if you're Mom & Pop liquor store in Italy with no U.S. involvement. But who knows? It could mean that your supplier is a U.S. based company and may not be allowed to supply you any more in the future.
In practice nobody gives a shit about a few cases of whiskey, but the same practice might be used for large shipments or for items that are undesirable for North Korea to obtain.