European leaders in Paris, U.S. and Russia discuss Ukraine alone in Riyadh

So, EU leaders are in full-on crisis mode. Again. This time, they’re scrambling to respond to a rather blunt questionnaire from Washington, yes, an actual questionnaire, that they have to think about during their meeting in Paris and that is asking what kind of security guarantees Europe is willing to provide Ukraine. But what worries Europe, and will these talks find any point of consensus?