North Korea could hit almost anywhere on earth with a ballistic missile, analysts say, a capability it has honed alongside a wide variety of shorter-range weapons with comprehensive testing that includes a record-setting number of launches in 2022.
In March and November, North Korea sent ballistic missiles soaring more than 6,000 km (3,700 miles) into space. The high-flying trajectories showed a weapon designed to hit another continent, or even deliver multiple warheads.
Pyongyang has also test-fired at least three intermediate-range ballistic missiles (IRBMs) over Japan, including an Oct. 4 flight where the missile - possibly a variant of the intermediate-range Hwasong-12 - landed about 3,200 km beyond Japan in the Pacific Ocean.
There are many questions over just how reliable and capable the North's biggest missiles are: it has yet to fully demonstrate some key technologies for ensuring a nuclear warhead survives its fiery decent through the atmosphere and at least some launches appear to have ended in failure.
But analysts say North Korea's flurry of testing shows it is fine-tuning missiles that could be used in a war, and that it has little interest in giving them up.
North Korea says its ballistic missile development is a legitimate exercise of its right as a sovereign state to defend itself from external threats, including hostile U.S. policy
It has said it rejects U.N. Security Council resolutions banning missile and nuclear programmes as an infringement of its sovereign rights. It has also said it has the right to space exploration as a sovereign country.
Although long-range weapons get more attention, North Korea has been pouring resources into shorter-range systems too, analysts say.
After historic denuclearisation talks between leader Kim Jong Un and U.S. President Donald Trump fell apart in 2019, Pyongyang rolled out new and increasingly capable short-range ballistic missiles (SRBMs), many of which can manoeuvre to confound missile defences.
Short-range weapons help it prepare for a potential confrontation with its neighbours, especially South Korea, analysts say, which hosts about 28,500 American troops. In North Korea's testing programme, short-range missiles seem to have been the most successful.
The North has also tested other advanced weapons, including "hypersonic" missiles, SRBMs for “tactical” nuclear attacks and new submarine launched ballistic missiles (SLBMs).
South Korea and the United States have warned since early 2022 that North Korea may resume nuclear testing for the first time since 2017. Analysts say that could help it perfect smaller nuclear warheads that can fit on a range of missiles.
"Kim announced plans to develop weapons systems ranging from tactical nuclear weapons to a nuclear-powered submarine and is ticking the boxes on his weapons wishlist through a series of tests," Hwang Ildo, of Seoul's Institute of Foreign Affairs and National Security, said in a recent report.
The warheads of tactical nuclear weapons have less explosive power but are meant for battlefield use, attacking specific targets relatively close to the launch point.
Targeting U.S. bases in South Korea with such weapons makes sense because the North Korean military does not have enough conventional warheads to meaningfully damage such facilities and prevent a conventional U.S. strike on North Korea, said Duyeon Kim, a North Korea expert at the U.S.-based Center for a New American Security.
"It would now be able to do so, while reserving its ICBMs and thermonuclear bombs to deter the United States from retaliatory annihilation of North Korea,” she said.
More mundane technology such as rocket fuel is also undergoing intense testing in North Korea. Solid fuel - which would allow missiles, including ICBMs - to be launched with little warning, is a particular focus.
On Dec. 16, scientists in North Korea tested what they called a “high-thrust” solid-fuel motor that appeared aimed at perfecting a large engine for an ICBM.
"One of Kim Jong Un's objectives... is to develop an ICBM propelled by solid-fuel engines, and if North Korea succeeds, it will become difficult for the U.S. to defend against Pyongyang’s nuclear arsenal, as signs of an ICBM launch using solid-fuel engines are hard to detect early," Hwang wrote.
(Reporting by Josh Smith; Editing by Gerry Doyle and Raju Gopalakrishnan)
