Is it really necessary to choose one or the other? > Why not just say "neither"?
Asia contains so many diverse elements that it is doubtful whether it makes much sense to ask if Russia might [or might not] 'belong' there.
One could probably argue, on the other hand, that Europe does have an identity, and that Russia is sufficiently different to be regarded as an 'outsider'.
The idea that Russia has been an "oriental power" for ages is a complicated and varied one. Despite its physical location in Eastern Europe, Russia's history, culture, and political identity are frequently connected with the East, notably via its Orthodox Christian past. Factors like the country's wide territorial extent, historical linkages with Asia and the Middle East, and different cultural and linguistic traditions have all contributed to this identification. It is crucial to emphasize, however, that this classification is not widely recognized and is open to interpretation and argument.