In a disorganised society where many are disadvantaged, it is natural to scavenge (or loot) to survive or even to better yourself. Look what happened in N'O.

The guys who took the components of unassembled greenhouses wanted stuff to improve their houses. Nobody was offering it to them, it was being sat on. If they did nothing, the goods would have gone to someone else. (maybe more deserving people or, maybe concentrating the wealth in the hands of a few slum landlords, too - but either way, in a country with almost zero administrative support, it's a simple rat race)

The trouble with international aid is that you have to do two things at once. You have to placate the immediate problems and keep the population satisfied, then you can work on the improvements. If you just try to put improvements in, then refugees will camp inside your greenhouses becasue they don't have decent homes yet. (Or steal the components before you even assemble them)

Aid has to be targeted and comprehensive, and involve the social/political structure of the target population.

After decades of rabidly pro-Israeli policy, no US voice has much credibility in Palestine, so don't even try to put your foot in your mouth!