I largely agree with BigDave1967. If the British, French and Ottomans are winning very swiftly and decisively at first, the Tsar will decide that this latest attempt to increase Russia's influence in the region was a bad idea and stop the war very soon after its beginning, probably with some concessions to the British and French if they want it. That might lead to Russia being actually less inclined to change than it was IOTL, since it will have suffered a defeat in a very brief war rather than in a long, drawn-out war that cost lots and lots of Russian lives.