 So Karim Shalom is the busiest of those border crossings, and it's just a couple miles from Rafah, the city you will recall that's at the southern end of the territory, and a couple months ago it was crammed with displaced Palestinians. But the Israeli military operations in Rafah have emptied out that city. It went from more than a million residents to fewer than 50,000, according to the UN. So the aid has to go deeper into Gaza, where the population is constantly on the move,