But why does it matter? Does historical barbarity justify present day barbarity? It doesn't, and we all know it doesn't.
It's not the case that Israel is held to a higher standard. Russia has been widely condemned, blocked from international finance, and faces severe sanctions. On top of that, western countries have given substantial military and intelligence aid to Ukraine. Russia had reasons for their invasion of Ukraine (just like Israel has its reasons), but so what? Russia being angry at Ukraine is not a justification for destroying the country.
I also take issue with your characterization that Gaza "started it". This is a 70+ year conflict with many chapters of violence in it, and innocent Palestinians make up the bulk of the casualties. Israel is not the victim here.
Finally, it's not accurate to talk about Israel/Gaza as two nations at war. Israel controls everything coming in and going out of Gaza, electricity, water, etc. Palestine is not an independent country or a state, it's part of Israel except its citizens have no rights.
Since we had a global war which almost destroyed civilization. https://en.wikipedia.org/wiki/Proportionality_(law)#Internat...