The first task in any peacekeeping mission is to negotiate a cessation of violence - that agreement has  to be credible and it has to carry penalties for  defection and it has to involve all parties - that means involving Kiev, Russia and the rebels - absent any one of the parties and the likelihood the others will commit is essentially zero

The second task is to agree on a buffer zone between the factions and the withdrawal of heavy artillery - that line of separation has been legally identified through the Minsk agreements monitored through the OSCE.

The third task is to place the burden of   implementation on the parties themselves - while Ramsussen talks a lot about what the rebels and Russia must concede he fails to mention what Kiev must give up.  One such concession is control of territory  or alternatively full autonomy for the region.

Rasmussen knows full well what happens if a third party tries to implement peace when the parties to the conflict are not committed - Bosnia.