FOBS has a much lower apogee for the same range, meaning it stays below the horizon longer (giving less time to intercept it.) https://stateofthenation.co/wp-c

FOBS has a much lower apogee for the same range, meaning it stays below the horizon longer (giving less time to intercept it.) https://stateofthenation.co/wp-content/uploads/2021/05/FOBS-OrbitDiagram.jpg https://stateofthenation.co/wp-content/uploads/2021/05/FOBS-... Furthermore, it can in principle come from any direction, which was relevant historically when it was expected that Soviet ICBMs would come over the North Pole.