ON ANY given day, a group of Palestinian children can be found kicking a football around on a patch of bright green artificial turf, a small oasis of respite from the daily hardships of life in the Aida refugee camp not far from Bethlehem.Beneath the grim shadow of the towering concrete wall that seals them off from the rest of the West Bank, the children train hard and dream big, enjoying their time together in one of the few safe spaces they know. But now, even this simple pleasure could be stolen from them.