Soviet countries use right hand fingers, western european coutntries left hand fingers
lol what are "Soviet countries"? :)) Since when Norway is a Soviet country?
In Latin "sinister" is "left" and "dexter" is "right". Here is whence a tradition to use right hand fingers came. Right hand is more associated with positive things in some countries and in Orthodox faith.
Left hand is less used, that's where I see the reason to wear wedding rings on left hand fingers.
western european coutntries left hand fingers
Not all of them. E.g. Greece, Germany, Spain, part of Netherlands, Austria etc.