Going off the slights and defeats perceived in the 19th and early 20th century: I would see Japan as a clear source of frustration and anger in the East, given the Russo-Japanese War. In Central Asia, perhaps a rerun of Afghanistan, as it was the site of the Great Game between Russia and Britain. In Europe, the Slavic nations and Scandinavia. Perhaps the Balkans and the Near East. Beyond that, given Fascism is anything but limited in its aims and not sane: Alaska in North America, and the threat of expansion in Asia. If it got especially lacking in sanity, as fascism is prone to do, it could seek expansion into Africa. Heck, even South America. Russia is the largest nation in the world, positioned within but alienated from the spheres of both Europe and Asia, in a place to seek land anywhere and everywhere. And there is a lot that Russia tried for but failed to get. Again, I reference Scandinavia and Manchuria. So Russia is truly a nation that could madly seek to conquer the world if it turns as wicked as fascism, and in a position to go far with that goal.
That is until it smacks into the British Empire, France, and the United States, the Japanese, and the other more minor powers it could go to war with. Minor nations could be ground under, bloodily. World Powers are a harder venture, and it would be another World War. It is also a matter of development and industry. On paper, Russia is in a stronger position than the Axis Powers of the OTL. In practice, barring industrialization, it is an underdeveloped power with far more potential than Germany, but which is not utilizing its potential (to evil ends) as Germany did. If Adolf can build only 20 factories and built 15, and Joey could build a 100 factories but only built 12, Adolf is in a better position than Joey.