Full-disclosure, lifted from another poster on another board
https://groups.google.com/forum/#!topic/soc.history.what-if/H1f-v7sAf6A
In OTL Alexander III died in 1894 at the age of 49 due to the kidney failure. Presumably, this was a byproduct of the train crash during which he hold the falling roof of a train car allowing people to escape (of course, this could also a byproduct of alcoholism but let's stick to more heroic option).
What if he is in a good health (why not? naturally, he was a very strong man) and lives all the way to the age of 75 dying in 1920?
In his domestic policies he was a strong conservative but intelligent enough to relax his attitude by expanding powers of "zemstvo" (parish councils) during the famine of 1891–1892 and the ensuing cholera epidemic when it became obvious that government's resources are not adequate for coping with the task. A positive side of his conservatism was relatively effective suppression of various "revolutionary" (terrorist) factions.
In practical terms, during his reign Russian economy experienced a high rater of a growth and while in OTL the most important Witte's reforms (stabilization of the Russian currency among them) happened during the next reign, he became Acting Minister of Ways and Communications and then Minister of Finances during Alexander's reign.
In his foreign policy the relations with Germany became chilly after dismissal of Bismark but did not escalate into a military confrontation. With regard to Bulgaria he exercised similar self-control and vetoed all proposals to intervene by force of arms. In Central Asian affairs he followed the traditional policy of gradually extending Russian domination without provoking conflict with the United Kingdom (in Panjdeh Incident he offered an arbitration that resulted in establishing a "final" birder), and he never allowed the bellicose partisans of a forward policy to get out of hand.
It can be assumed that he would not approve of the risky Far Eastern adventures in which his son got involved so the war with Japan could be avoided and I strongly suspect that he would not be provoked by the Austrian-Serbian conflict. Anyway, when in OTL Nicky finally understood what he is getting into and asked Chief of the General Staff to stop mobilization he got an answer that this is a matter too serious to be stopped. I have VERY SERIOUS doubts that anybody would risk to give such an answer to Alexander. An additional consideration is that, unlike Nicky who was very timid toward his uncles (holding important positions in the Army and Navy), Alexander was a dominating figure.
Of course, his domestic conservatism had its downside because a lot of "steam" had been just "kept under the lid". However, if the economy kept growing and the major wars are avoided, the big-scale political disturbances were highly unlikely: Russian peasantry (a vast majority of the population) had been quite conservative and, unless pushed too far (as was happening during R-J War and WWI), was reasonably loyal to the regime and not deeply touched by the revolutionary propagandists (who usually were a completely alien element to them). Army, being composed predominantly of the peasants, also was quite loyal, unless pushed through the Hell (as happened during WWI but not R-J War).
Proletariat was in its growing stage so some problems in that are to be expected but in OTL they were mostly along the same lines as in the rest of the developed world: creation of the unions, economic demands, calls for a better labor regulations, etc. The "educated classes" had been noisy but this was traditional Russian phenomena, not dangerous unless the general conditions provided it with some traction among the "working classes" (a major crisis would be needed for this to happen). Thing often overlooked is the fact that in OTL Russian PROFESSIONAL workers (those working in the big industrial plans, railroad personnel, etc.) had been doing quite well economically which, of course, did not prevent them from going to strike but even here and now I can see from time to time the workers of the local GE plant waddling (beer bellies are being something of a trademark) to the sidewalk with the placards.
In other words, revolution would be extremely unlikely, especially if government eventually adds some "icing on a cake" (Duma or something of the kind). In general, with extra decades of peace Russia is much stronger economically than in OTL.
OTOH, many of the issues in the "unsettled areas", specifically on the Pacific, are already settled so the reason for conflict like the R-J War is probably not there.
It could be expected that after Alexander's death some liberalization is going to happen just because Nicky is a weakling (even if a very stubborn one on all the wrong things).
So, in 1920 Nicky picks the reins. What's next?