Well, diplomatically, very little needs to be done. Russia OTL was pretty chummy with the USA. By WW1, the Russians were clearly needed in the Allies.
Add in a setting where Russia avoids provoking Germany in WW1, indeed, the Czar might call for diplomacy instead of troops. If he does, Austria has probably succeeded in crushing Serbia, but they've eaten slow poison and the Czar know this...Austria is going to face internal resistance that will slowly sap the will of the State to survive.
Unlike the other states in Europe, Russia tended to be inwardly focused after its humiliation by the Japanese, a lesson not forgotten by Czar Nicholas II, who recognized that Russia needed to modernize--even to the point of creating a Duma with some democratic powers.
By 1940, Russia has adopted many of the reforms demanded by the peasants, and stolen much of the thunder of would be revolutionaries. Stalin, Trotsky, Lenin, and many of the would be Communist Revolutionaries spend their days counting trees in Siberia. Russia is also slowly industrializing, benefiting a great deal from British investment and retaining a good friendship with the United States.
Still some kind of WW2 is inevitable, and Russia has already been attacked repeatedly over the Manchurian Border by Japan. In the Western Side of the equation, the Poles continue to agitate for their independence--the uprising of 1932 was one more failed movement in the list of generational uprisings. So, the Russians begin to move into Manchuria, provoked by Japan--and with Chiang Kai-shek's blessing. Russia will ultimately include Mongolia and Manchuria, but China will remain independent.
The Situation in the West would probably be Germany and France at each other's throats, and Austria slowly falling apart. Russia isn't missing much in Europe--but Against Japan, the Russians have the major advantage. The Russians Navy might be beatable by Japan, but their land armies are that much stronger--in mere months, the Russians have rolled Japan out of Manchuria and stand at the Yalu River--a Boundary that the Japanese will ultimately sue for peace at, having watched all of their dreams go to pieces as a result.
For the next 70 years, Russia remains a slowly developing and democratizing country, as the Czar becomes a UK style figurehead. This explains why so many Chinese immigrate to Russia throughout the years--because Russia has a pretty good idea of how to run its affairs and a Post-Chiang China is still struggling...