Reem Zeidan walked with two of her children for hours overnight to get to an aid distribution site in Gaza. Zeidan wanted to get a bag of flour to make bread, and her 5-year-old daughter, Razan, was hoping for biscuits. The mother of eight never made it to the aid site. Zeidan would soon join the dozens killed as they struggled to secure food, underscoring the pitfalls of a new aid system in which tens of thousands of Palestinians must walk long distances — often through areas controlled by the Israeli military — to have a chance of getting a fraction of the limited aid being handed out. The United Nations, which had previously run a network of hundreds of aid distribution points across Gaza but has since been sidelined by Israel, warned that reducing aid distribution to the U.S.- and Israel-backed Gaza Humanitarian Foundation’s four sites would be chaotic, insufficient and dangerous. Humanitarian groups have railed against the new aid system in Gaza, saying it has put civilian liv...