A damaged United Nations vehicle is seen in front of a hospital after a UN employee was killed in an attack on a vehicle in Gaza, according to Israeli media. Ali Jadallah/Anadolu/Getty ImagesThe US has assessed that Israel has amassed enough troops on the edge of Gaza’s southernmost city of Rafah to launch a full-scale incursion in the coming days, but senior American officials are unsure if a decision to carry out the offensive has been made, two senior administration officials told CNN.The White House believes an Israeli ground offensive in Rafah would be a mistake and is…