The Russian Navy is still sheltering in its base in Crimea after a sweeping Ukrainian drone attack last week.Russia’s Black Sea Fleet dwarfs the remnants of the Ukrainian Navy and should by all accounts be able to launch missiles and amphibious landings off Ukrainian shores with relative impunity.In March, Ukraine hit a Russian landing ship in the port of Berdyansk with a ballistic missile, forcing the crew to scuttle the vessel.USVs, even if they don’t end up doing much damage, are a tricky problem for navies to deal with.Without good options for preventing future attacks and an eroding grip on the Black Sea, the Russian Navy will likely stay cautious."