Russia is indeed threatened by the Chinese encroachment, to say nothing of separatist movement in the Islamic parts of Southern Russia. What you may see is a contracted, but leaner and meaner, Russia in the relatively long-term future. I think the struggle of Russia will not be so much one of Third World immigration, but the revitalization of the spirit of the Russian peoples. The declining birthrate is certainly a negative; the budding re-spiritualization and return to its Christian roots is a positive.
The same can be said of the other Eastern nations of the Continent as well. Ultimately, I believe mass Third World immigration will be the downfall of the West; assuming Russia and Eastern Europe avoid that, I think they will compete with East Asian nations for global supremacy.
I would also add Spain, Portugal, Iceland, and, considering recent developments, possibly Denmark to my list as well.
If couched right, I believe Russia is a natural ally of ours in the long term. We need to get our own house in order and work with them. I don't see them as devious as the old USSR at all. And I think they are the ones we should be courting instead of China.
Your comments are well taken. I belive that you're on the right track and I do see that Russia might be one of the last white majority nations to go under. It will be interesting to watch things play out. Of course that's providing things remain peaceful, which I'm not inclined to buy into in the long term.