So, the POD in a TL I've been planning is during the 11th Russo-Turkish War, fought by Russia to increase its eastern power, with the Ottoman's mistreatment of Christian minorities in present-day Bulgaria as a cassis belli, the Russians threatened to conquer Istanbul. Prime Minister Disraeli urged Germany and Austria-Hungary to fight and prevent the Russians from accomplishing this. This never went through IOTL, as the Russians sued for peace soon after. But if they hadn't, then an early Great War could occur.
My question is, what would the sides look like? Obviously, Britain, Germany, and the Austro-Hungarian Empire would be part of one faction, and Russia another, but who else would join? I was thinking France and Italy join with Russia to reclaim territory from Germany and Austria respectively, but that might be ASB. Maybe China would fight against Britain, but IDK.
Also, what would such a war be fought like, and what might be its consequences?