> to the best of my knowledge, a proportionality between casualties on the two sides is not an expectation of any rules of war

If you were talking about combatants, you'd be correct. The main point about Gaza is that the majority of those who are killed are civilians[1]. And most civilized countries recognize[2] that civilians should be spared during armed conflicts.

[1]: https://web.archive.org/web/20250821135825/https://www.thegu...

[2]: https://en.wikipedia.org/wiki/Protocol_I_to_the_Geneva_Conve...