North Korea tested its own hypersonic missile in January 2022. South Korea has spent the three years since closing the gap. The successful test of the Hyunmoo-5H glide vehicle from a mobile launch platform at the Anheung test range in February 2025 demonstrated a range and speed that places every significant military installation in North Korea within a six-minute strike window — including the deeply buried underground facilities that conventional ballistic missiles struggle to threaten credibly.

The Hyunmoo-5H uses a boost-glide trajectory: a solid-fuel rocket booster accelerates the vehicle to hypersonic speed before separating, leaving a manoeuvrable glide vehicle that can adjust its flight path in ways that defeat fixed ballistic missile defence interceptors designed for predictable re-entry trajectories. Terminal guidance uses a combination of inertial navigation, GPS, and terrain-matching imaging that Agency for Defense Development officials claim achieves a circular error probable of under three metres at maximum range.

South Korea's missile programme has operated under US-imposed range and payload restrictions since 1979 as part of a technology transfer agreement. Those restrictions were fully lifted in 2021, removing the last constraint on development of longer-range and higher-payload systems. The Hyunmoo-5H programme, begun immediately after the restrictions lapsed, has progressed from concept to successful test in under four years — a development timeline that has surprised even optimistic observers within the Korean defence establishment.

Japan and Australia have both requested technical briefings on the system. The United States has described the test as "consistent with Alliance deterrence objectives" — diplomatic language that defence analysts interpret as a tacit endorsement of Seoul's expanded strike capability.

"Deterrence requires that the adversary calculate correctly," said Defense Minister Shin Won-sik. "We have improved the accuracy of their calculations."