A hypersonic glide vehicle (HGV) is a type of warhead for ballistic missiles that can maneuver and glide at hypersonic speed. It is used in conjunction with ballistic missiles to significantly change their trajectories after launch. Conventional ballistic missiles follow a predictable ballistic trajectory and are vulnerable to interception by the latest anti-ballistic missile (ABM) systems. The in-flight maneuverability of HGVs makes them unpredictable, allowing them to effectively evade air defenses. As of 2022, hypersonic glide vehicles are the subject of an arms race.