And we agree this was wrong, right? The 1948 war isn't even relevant here. Israel is required, by international law, to withdraw to the 1967 borders.
But also, the war was started because the Zionists unilaterally decided to create a new country in the middle of somebody else's land, displacing hundreds of thousands of people from homes they'd lived in for generations.
Seriously, try a little empathy exercise here, imagine that some foreign power unilaterally declared that over 50% of your country was now theirs. And if you knew that their true intent was to slowly but surely take over 100% and drive you out completely. Would you shrug your shoulders and accept this? Do you think it would be unreasonable if your government went to war? Do you think, even for a second, that they wouldn't?