I would say that negotiating with all the parties to the problem is always a good solution.
I'm just not sure if Russia is ready to negotiate, because, as you said, Russia is not going away. I'm glad that people like the Russian ambassador to Canada yesterday on TV said, “This is not even on our minds, entering into Ukraine.” At the same time, as you said, MPs from the Russian Duma are going there to sort of give passports to Ukrainians. This goes back to the Georgian play as they did over there. Suddenly it's, “We have a whole bunch of Russian citizens so we have to protect them,” or “We came in only to protect them.”
Yes, if you can somehow convince them, but I'm not sure that they are convincible. I would be very careful how you negotiate with them. If Canada can somehow be that ambassador and bring the three sides, including the European Union, together, I would be definitely for it.
I would just keep on telling everybody, that includes the U.S. and Russia, that they have signed an agreement; they have put their signatures on it, so stick to it. Don't play games, just stick to the agreement you have signed.