Nordic / Mediterranean

Estonia was a very particular case during World War 2
Estonia got annexed by the Soviet Union during the Molotov-Von Ribbentrop Pact, however during Germany's attack on Soviet territory, Estonia was annexed by the Axis, leaving the citizens witnessing the Soviets burning and destroyed buildings (it's an actual tactic of war, called "Scorched Earth"). The Estonian army then joined Nazi Germany, but whilst the campaign, Estonia changed side yet again by allying themselves with the British, and being part of a small sea force in the area.

Some Estonians even joined the Finnish army

Overall, Estonia isn't a country you want to be allied with. Not even we Italians change sides twice in the same war