Lithuania became a "Baltic" state only after World War I

The Russian Empire considered its "Baltic" provinces the lands of present-day Finland (ceded to the Russian Empire in 1809, after the Finnish War), Estonia and Latvia. The lands of present-day Lithuania were considered part of Western Russia. It was only after World War I that the term "Baltic States" was used to refer to countries by the Baltic Sea that gained independence from the former Russian Empire. Originally, there were four Baltic States: Estonia, Latvia, Lithuania, and Finland -- which, in 1924, joined Sweden, Norway, Denmark, and Iceland in a precursor of the Nordic Council.

Russia's Baltic Provinces before and after the 1809 Finnish War:

Left: 1777, Detail: Kitchin/Guthrie: "Russia in Europe," from the National Library of Finland: http://www.doria.fi

Right: 1852, Detail: Stieler/Justus Perthes: "European Russia," from www.davidrumsey.com

With Finland, and soon Sweden, in NATO, "Russia's neighbors are close to creating a 'NATO Sea' that could deter Russia and help Ukraine, says Estonia's defense minister Hanno Pevkur." (Sinead Baker in www.BusinessInsider.com)