It's up to them and Israeli to decide, I guess. Not wanting to help is not the same as killing. If some stranger comes to your home, you're not obliged to let him in and it won't be kill, even if he died afterwards. World is cruel and nobody obliged to nobody, especially at population levels. It's much easier to help single person, of course, but accommodating millions is another matter.
> If some stranger comes to your home, you're not obliged to let him in
Sure.
But if you go over to where a stranger lives and build a wall around them. You are responsible if they then starve to death.
If another stranger is delivering food to a different stranger and you kill the food deliverer. You are responsible for that mans death.
These analogies are much more relevant to the discussion. Isreal is disallowing people from delivering food and has even killed people that do (leading to organizations like word food kitchen to leave).
