>>39
You could start by putting an end to the illegal colonization as described above, then by showing the palestinians (and whoever else is watching) some acts of good faith, e.g. by building them water pumps and by sending over food if they need it, maybe helping them with agriculture and giving them your old cars. Provide books if they want them. You might think it's way too expensive, but I believe that paying the military to be constantly on the watch for imminent attacks is a lot more expensive. And with all that, you can hope that someday that big wall will be unnecessary.
Would they accept it? If they did, would it be like aid to Africa and NK where the leaders take it all while the people still starve? How would you prevent it from being like the US `rebuilding' attempts where various factions see those who accept help as collaborators and attack them? Also consider that one of the easiest ways to stay in power as a despot is to had a perpetual enemy. There are some on both sides that have a lot to lose by achieving peace.