I hope Putin comes down hard on Ukraine's government, and those associated with it, but our government targeted infrastructure in Iraq; lots of people died because of lack of electricity and water and sewage processing plants. There should absolutely be consequences for mass murdering people, but I will agree with you that the better thing for Russia to do would be to better arm Syria and Lebanon.
I'm not saying Putin shouldn't retaliate, I just hope his choice doesn't target places that would be disastrous to civilians. Ironically I'd argue that if Putin fought this war like the US does, then most likely the Ukrainian people would demand that their government actually cooperate with Russia to bring the war to an end, but I just can't agree with harmful acts towards civilians to bring it about.
Also honestly Western countries don't care about the lives of civilians in Ukraine, and they definitely don't care about the lives of people in the middle east. I think perhaps the better option, and frankly with the best outcome, is to try and convince as many countries in the global South to cut ties with Western countries and reduce majorly their sale of oil to them, and especially preferably during winter to see if maybe that sends a message.