['Hello down there, Sultan!\n\nAnything we need to talk about early, or should we just see what happens early?\n\nBest,\n\n- Kaiser', 'Eh, I have the luxury of a boring country that CAN chill out and see how things shake out. \nAnd as much as I personally enjoy opening to Tyrolia as Germany, other people tend to look at me weird if I suggest it, so...I guess all I can really five into is to ask that you give me a heads up if you decide to pick a fight with a mutual neighbor so I can pile on', "So, you were going for the Slingshot Juggernaut, and had the rug pulled out, huh?  That hurts.  And Austria is in no position to provide much help.\n\nWhat's the plan from this point?", "My hands are tied with my positioning and an NAP that runs through the end of this year, but I'm happy to work as an intermediary with you and Austria to help coordinate.\n\nI've given you one bit of help - Russia can't build in Warsaw, so it takes one unit out of the South.", "Ugh, what a pain in the ass. I can't even rotate on him in a meaningful time frame, and Austria's going to be no help any time soon beyond protecting Bulgaria this turn."]
You could take him down together, unless he's working with Italy.  Even if he's not, Italy's going to feed on Austria - he's pretty committed - and come after you since you're exposed.  The upside is just that they wouldn't likely be explicitly helping each other.

I don't have anything preventing me from going at Italy, and he's really wrecking everything right now.  Plus, silent.  As far as I know, towards everyone.