ROME — During a visit to Moscow in 1980, Marco Minniti, a bald and bold young functionary in the Italian Communist Party, mortified his comrades by asking a Red Army general why the Soviets had occupied Afghanistan. The general pointed south on a map and explained that the faraway land mattered for his country’s national security.

Now, decades later, it is Mr. Minniti, Italy’s powerful interior minister and the hard-nosed veteran of its intelligence apparatus, who is looking south — but to Africa, which he calls the “mirror of Europe.”

A mass migration streaming up Africa, through Libya and across the Mediterranean — enabled by human traffickers and exploited by political populists — poses an existential challenge to his center-left government, not to mention his country and continent.

To stem the flow of migrants — and the potential infiltration of terrorists — Mr. Minniti, a 61-year-old former communist, is calling on his vast government experience, Calabrian brio and the sub-rosa relationships he developed as Italy’s “Lord of the Spies.”