I contrabbandieri di Santa Lucia (1979)

A revolution in Iran halts a heroin shipment, but an alliance of crime families is set on getting it to the US. They decide to run the drug through an unsuspecting network of good-natured, local smugglers in Naples, while an international anti-narcotics agent rushes to shut their operation down. Betrayals and divided loyalties lead to a final, bloody confrontation in America.