Since when don't innocent people die in war? Since when is war justified? Since when has any act of war or terror been proportional?
There is a lot of language (used by both sides) that manipulate what people understand - apartheid and occupation come to mind.
Israel took the West Bank, Golan Heights, Nd the Gaza Strip in battle. The land belonged to Syria, Jordan, and Egypt. Israel attacked first. The Arab States closed off the Suez Canal so Israel was without supplies. Then the three nations amassed on her borders - readying for attack.
Israel used the element of surprise and got in first.
Enter the United Nations who had a law that said that the nation who attacked first could not keep the spoils of war, therefore Israel was 'occupying' the land. Yet Russia has taken land during the past 20 years and there is no outcry against her occupying land.
With regard to apartheid, there is no comparison between the different states that South Africa gave to the different tribes. They were not cut off from supplies. They had plenty of food and water. They couldn't vote. They needed passes. They weren't allowed to be educated to the same level as whites. They weren't allowed to earn the same as a white men. There were also crimes on both sides.
When the ANC wanted to ignore it's own sins and punish only the white man, Nelson Mandela said no.
Two wrongs don't make a right.
As for proportional retaliation, the concept is bizarre. Not that I believe in God's, but isn't the idiom 'Revenge is the Lord's.'
Hamas has been given billions over the past 18 years. That money could have been used to build infrastructure, thereby making them independent of Israel. The majority of Palestinians still support Hamas.
It is a complex and tragic situation.
The basic problem, though, is that the Arabs/Muslims don't want Israel to exist, and there is no peaceful solution