The Serbians meanwhile can advance, I have chosen a careful advance and only taken a few Austrian provinces but Festung Peterwardein fell, so Belgrade seems to be safe for the moment. I have a continous front line from Montenegro to Bazias with entrenched Serbians.
It was infuriating to see after turn 5 the losses: Central Powers 100.000, Eastern Entente 200.000, Western Entente: 5.000

THANKS FRANCE FOR HONOURING OUR TREATY WHERE WE WOULD BOTH ATTACK GERMANY AT THE SAME TIME TO DIVIDE THEIR FORCES!
But now it has changed, the Germans seem to have railed a lot of their forces back to the French border and there seem to be really large border "skirmishes" there. No territory actually changed hands, but now 150.000 WE forces have died. I don't really know for what gain. But hey, we're talking about WW1 here!
I think I will restart the game with huge AI bonuses. Maybe that will help them a little more.