North Korea has surged ahead in recent years in an inter-Korean arms race that has led to a proliferation of short-range missiles on the peninsula and left Pyongyang closer than ever to deploying tactical nuclear weapons.
North Korea's yearslong quest to develop precision missiles capable of evading detection and striking targets in South Korea has accelerated in the wake of the country's 2018 self-imposed moratorium on testing its larger intercontinental ballistic missiles (ICBMs).
Meanwhile, a 2017 agreement between Washington and Seoul lifted bilateral limits on South Korean missile payloads, leading to the development of at least one heavier weapon that could play a key role in strategies aimed at preempting North Korean attacks or "decapitating" its leadership.