How would Russia be able to get access to such a base? Between Russia and Serbia are Ukraine, its enemy, Moldova, and the NATO countries Bulgaria, Romania and Hungary. The only passage to Serbia through non-NATO territory would be from the Adriatic Sea through Bosnia—and that would be problematic, since Bosnia’s coastline is only 12 miles long and its only coastal town is Neum, which is not a seaport.
“How would Russia be able to get access to such a base?”
Obviously, invasion is not a detraction for Li’ Putin.
I hope he is just spouting off in a “I control the world” rants!
Bosnia used to have another bit of coast at Herceg Novi, near the entrance to the Bay of Kotor, but Tito gave Herceg Novi and the entire Bay of Kotor area to Montenegro. In earlier times Neum and Herceg Novi were part of Ottoman Bosnia and Hercegovina because the Republic of Ragusa (Dubrovnik) did not want a land frontier with Venetian territory. The Bay of Kotor was part of Venetian Dalmatia. Herceg Novi is pretty small so I don't know if it would have been of much use as a port--but it's in a mostly-Orthodox area. I think the part of Bosnia near Neum is mostly populated by Bosnian Croats who may not be particularly pro-Russian.