Russia's Role in the Geula
We have many times talked about the statement attributed to the Gr"a that when Russian ships pass through the Bosporus Strait and the Dardanelles, we should put on our Shabbat clothes to ready ourselves for the coming of Mashiah.
Rav Fish, in his newsletter for Parshat Toledot (p. 10), claims that there is new evidence that has come forth that the statement comes from Rav Shimshon of Ostropoli ZY"A in his no-longer-extant book "Mahane Dan". That would mean that the source is at least a century before the Gr"a.
The evidence comes from a book called Yosef Kadisha, published in 5775 in the Yiddish language (download relevant excerpt here). I am not fluent in Yiddish so I cannot translate what it says, but I will translate what Rav Fish says:
And in the book Yosef Kadisha, he brings from Harav Haga'on Rav Yaakov Gellis ZT"L, who heard from the Maharil Diskin ZT"L, who had the book "Mahane Dan" by Rav Shimshon Ostropoli HY"D, that there it is brought down the tradition about the Dardanelles that the Russians will pass through there with the purpose of coming to capture the Land of Israel. And it is brought down there the process which will occur to the Land of Israel - that first, it will be ruled by the Turks, and afterwards, the British, and finally, the Russians will come, and then, we should wear our Yom Tov garments for the honor of Mashiah.(Regarding how the Maharil Diskin ZT"L could have seen the Mahane Dan when it was supposedly lost centuries ago, see the discussion here.)
It seems from here that the statement of Russians coming is not just to capture Turkey - it's to capture the Land of Israel!
With the Russians operating in nearby Syria (עד הנהר הגדול נהר פרת) with nuclear subs in the Mediterranean, we should expect the unexpected.