The Fractional Orbital Bombardment System (FOBS) was a Soviet ICBM program in the 1960s that after launch would go into a low Earth orbit and would then de-orbit for an attack. It had no range limit and the orbital flight path would not reveal the target location. This would allow a path to North America over the South Pole, hitting targets from the south, which is the opposite direction from which NORAD early warning systems are oriented. The Soviets developed three missiles to employ FOBS, with only one entering service: The SALT II agreement (1979) prohibited the deployment of FOBS systems: