Do we know for certain that Putin isn’t on Iran’s side here, against Israel?
No, we don’t, but they will during the tribulation.
Putin is on Putin’s side.
Part of the story here, and why the US is sending a war fleet to the eastern Mediterranean area, is because Russia has a strong presence in Syria. Russia can influence Hezbullah (and Iran) in Lebanon. If Hezbullah enters the fray against Israel the US could provide support from the sea, and from our forces in southern Syria and northern Iraq. If Russia is seen as letting Hezbullah loose on Israel, the US and allies can potentially argue this is a new front of Russian aggression - or really any argument the US wants to take since Hezbullah is believed to have been part of the bombing of the Marine barracks back under Reagan - though Islamic Jihad took credit for it, they are all closely aligned and backed by Iran.
But it only gets uglier from there. So hope Putin understands that escalation is not in his interest and if he can keep a lid on Lebanon he does. It’s really in nobody’s interest to open a second front. Another tidbit for thought, Iran is supplying Russia with drones, so it is possible that Iran learned some tactics in the Ukraine war and may have or may will deploy them in Gaza or from Lebanon.
So if I had to make a guess today, Russia will keep a lid on Hezbullah in Lebanon because the alliance against Russia will come with any excuse to open a new front against Russia.
I think we all know Iran and Russia are allies.