Quote Originally Posted by adoc
Technically it's always been "на", I am not sure how it suddenly became "в".
It is obvious why. Nа is used for Islands, areas, not countries. Na implies Ukraine is a region (of Russia), and not a country. The reason why it is Na Ukraine is because it originally was a region of the Russian empire. Since independance, and since it is a country in its own right, people have started using V (in Ukraine).