You have to have some kind of solution in the Balkans between Russia and Austria. Perhaps Austria is less expansionist due to internal problems and both sides are willing to negotiate in a conference mediated by the Germans. Clear spheres of influence are set, Turkey is left out. This drives the Turks to the British side, who now have renewed Russophobia. However, this is still not enough for WW1 to actually happen, as France is not suicidal. You have to have some kind of crisis, and have at least the Italians firmly in the Entente for them to even consider war. Maybe after the said conference, the British start meddling in the Balkans, trying to create a counterweight, such as Greece and Romania. This is a big enough alliance that could give the Entente some confidence, should any crisis arise. Maybe include Persia as well. Perhaps even Sweden.