As per the title, we’re assuming for whatever reason Russia decides to intervene on the side of the Shogunate, say Russia had a lot more invested in the Japanese Shogunate government and decided that military intervention in some form would be necessary. What next? Would the conflict escalate between neighboring Great Powers?
Just curious, how exactly could Russia interfere in any meaningful way? Below is a photo of the flagship (and the biggest ship) of the Siberian flotilla in 1850 - 70s, corvette “America”
And here is almost the whole Pacific fleet (Siberian flotilla) in the late 1870. On the right 2 armored frigates and 3 clippers, in the center “America”and 2 tugboats, on the back armed merchant steamships of the Voluntary Fleet. Strengthening of the fleet started only after 1880.
Taking into an account that port of Vladivostok was founded only in 1880 and Trans Siberian Railroad was not completed even in 1904, and that Witte conducted his financial reform only in 1896, it is easy to figure out that by the time of Meiji Restoration Russia did not have meaningful navy or troops on the Far East for any military intervention and did not have money for serious investment into Japan.