CAIRO (AP) — An Israeli tank brigade has seized control of the Gaza Strip side of the Rafah border crossing with Egypt, moving ahead with an offensive in the southern city even as cease-fire negotiations with Hamas remain on a knife’s edge. The development on Tuesday comes after hours of whiplash in the Israel-Hamas war. The militant group on Monday said it accepted an Egyptian-Qatari mediated cease-fire proposal. Israel, meanwhile, insisted the deal did not meet its core demands. The high-stakes diplomatic moves and military brinkmanship left a glimmer of hope alive — but only barely — for an accord that could bring at least a pause in the 7-month-old war that has devastated the Gaza Strip.