Geopolitik 101
Access to European ice-free ports has always been critical to Russian foreign and military policy. That explains their interest in the Baltic (Latvia, Lithuania and Estonia) and Black (Crimea) Seas .
One of my favorite fictional heroes, Capt Horatio Hornblower, played a major role in the Royal Navy's Napoleonic-era Baltic campaign
(In CS Forester's novel Commodore Hornblower).