Since the railway isn't even complete and the Russians need every scrap of supply line for themselves, quite a bit.
Ammo and spare parts for a fleet are rather trivial in bulk in comparison to supplies for an army.
No nation calls for help with all the attendant shame and costs if they still think they can win on their own.
Austria in WWI, against Serbia and Russia. Italy after Caporetto. Stalin was rather shrill about a second front from 1941 to late 1943. Italy in Grecia and Africa 1941. France in WWI and 1940.
"Think they can still win on their own" is a psychological variable that is subject to divergence, it is not something engraved in stone for every possible TL.
1) The French have no obligation under a defensive alliance to join the Russians in the war against Japan and trying to grab parts of Korea and Manchuria is no defensive act.
So it wasn't A-H attacking Serbia in 1914, yet they called on German garantee of aid and Germany granted it. Honoring the terms of the alliance on their own and answering the ally's request is something different.
2) The Russians need French aid in modernizing desperately, don't feel any desire to make the concessions involved in getting Paris to bail them out, and don't think they need the help until it is too late to win.
3) In OTL the French barely tolerated the Russian fleet off the coast of French Indochina and offered no aid whatsoever. Yet somehow the alliance survived.
4) History is filled with defensive alliances which survived and prospered without all members joining every foreign adventure launched by one member.
Again, here's the crux of our disagreement about the scenario. You think Russian confidence is a constant that cannot be ever subject to divergence, notwithstanding the fact they were getting a string of defeats before Tsushima. I disgree. Maybe you should just agree to disgree on this. I've seen far strange non-ASB PoDs than this.
5) Having concluded that German expansionism was the primary threat, due primarily to Germany's naval race, the British would not be dispensing with the Entente Cordiale so quickly.
The Entente Cordiale was a tentative, shaky, and half-hearted thing up to 1914, and only German invasion of Belgium crystallized it into a strategic long-term alliance. Had the Germans agreed to a curbing of the naval buidup, the British would have been to crumple it very quickly. There were serious talks about a Anglo-German reapproachement and possible alliance again in 1907-9, and serious feelers again in 1912-3 (for this reason, some historians posit that had not WWI exploded in 1914, UK and DE would have found an agreement, since the naval buildup and the attendant scare was dwindling). Or, if the Russians or the French had done anything serious (like beating up Japan) to show them any more strategically threatening, the British would have crumpled the Entente Cordiale equally quickly. It was a somewhat innatural pairing between old enemies up to 1915. WIthout the naval scare, it would have never happened. And the naval scare is quite subject to divergence.
6) Positing Great Britain joining the Central Powers over the Russo-Japanese War crosses the line into ASB territory.
Russian victory in this war would move them away from any repprochement with the British (the Russo-British Entente of 1907 is butterflied away), since they would still look like main strategic enemy of London. In this outlook, even the Entente Cordiale is reassessed and its value questioned, and more energetic efforts are made for a detente with the Germans. If the Russians win the war with French help, then the Dual Alliance has shown her effectiveness to trounce a British ally, using naval power. The British reassess their options, and deem again Franco-Russian naval power as the main threat, not German one. In this outlook, they have no good reason not to join the Central Powers. No real strategic tension with Germany besides the naval buildup. Two slightly different scenarioes: Russian victory in the war by their own resources: No Entente Britian. Russian victory with French help: CP Britain.
7) Given Russia's many difficulties and defeats, followed by inevitable revolt, even if the Russians pull out a victory at Tsushima it is far too late for them to appear threatening to Britain, or much beyond marginally competent. If that.
Weren't they modernizing ? If the Germans are aware of that, so the British.
8) The continuing pressure on Russia's allies in the Balkans will do nothing to improve relations between St Petersburg and Vienna with Berlin supporting Vienna all the way. Foolish, but there you are.
Yep, but this does not affect Britain's position much. As far as UK was concerned, they worried about Russian encroachements on the Ottomans, not the Austrians.
9) Likewise this position that Germany solely saw Russia as a potential enemy because of the alliance with France is wrong.
It's the difference between potential enemy (to a degree, no Great Power completely trusted any other, and even a war with a current ally was never completely outlandish to military and political planners; Ask Conrad and his shrill requests for a pre-emptive war on Italy) and sure enemy.