There isn't a war, according to one of the combatants, so "ending the war" is a too vague. What does "end the war" mean when one of the combatants claims that there is no war? I think it's better to discuss how to end one the nasty results, and I chose the deportations of children. Not for any particular reason, just because it's of the concrete things we all want to stop.
The Russians have deported a staggering number of children (almost as many children as live in Berlin), both from areas near the frontline and areas far from it. Could you describe what the west might to do to stop those deportations? Something more effective than delivering weapons?