Seems a bit off topic for the British Politics thread ....
The UK recognizes Israel as do 163 of 193 UN Members, of the 30 that don't recognise Israel 17 are Arab League and 9 others are from the Organisation of Islamic Co-operation, the other four used to be those bastions of democracy North Korea, Bolivia, Cuba and Venezuela, not sure if that's still accurate though.
So whilst someone might hold a personal view on the the Jews being "terrorists when a small militarized group of them backed by US funds and weaponry immigrated into Palestine and then took over the country" the vast majority of world nations would disagree with that ... doesn't make you or them correct, but it puts the question off Israel's right to exist into clear focus.
Once you get past the right to exist then the rest is just plain old tribal warfare - Palestinians have fired some 20,000 rockets and mortars at Israel ... Israel have fired far fewer but then far bigger ordinance of their own ... there are no winners just victims.
Blaming one side more than the other? That might sound good but in reality all it does is perpetuate the conflict.
I've no idea what the answer is, Israel isn't moving and Hamas will never accept their existence ... that's all good news for arms manufacturers and all bad news for civilians ...