It is said that sometimes, diplomacy is the art of telling a man to go to Hell in such a way that he looks forward to the trip (attribution unknown). That is, the art of saying things indirectly.
But that noted, as I review the situation in Ukraine and Russia, I wonder if a bit more directness directed towards the Russians might be helpful. Specifically, several treaties signed by Russia--or by the Soviet Union before it and renewed by Russia--prohibit aggressive war and the redrawing of borders by force. So instead of politely talking about the matter, just say
As a signatory to the United Nations Charter, Helsinki Accords, Geneva Conventions, as well as the treaties ending the Soviet Union, Russia needs to honor these treaties and immediately cease its illegal war, withdraw from all Ukrainian territory (1991 boundaries), and deliver those generals involved in long range attacks on civilian targets for trial on war crimes.
Economic sanctions against Russia, including against trading partners buying Russian oil and natural gas, will continue until this is done. NATO will also continue to provide arms to Ukraine for its defense.
More or less, if Putin wants his neo-Soviet experiment, he can deal with how we treated his Soviet ancestors. The USSR was an evil empire; the renewal of the USSR by Putin is the same. We ought to treat it that way.
