October 23, 2022:
A recent round of North Korean ballistic missile tests revealed that a new method for launching ballistic missiles had been developed. This one involved the use of an underwater launch tube placed in lakes and used to launch SLBMs (Submarine Launched Ballistic Missile). North Korea later claimed that this lake based SLBM launch involved a production model of their SLBM using a nuclear warhead that successfully detonated above the water. This is called an air burst and is the most efficient way to use a nuclear weapon. But there was no nuclear warhead on this SLBM because no radioactivity could be found where the missile landed. North Korea already has land and railroad train silos for its ballistic missiles. Air delivery (by fighter-bomber) was never an option because North Korean warplanes are so old and unmaintained as to be useless for combat, plus the air defenses for South Korea and Japan outmatch the best planes even China can field.
In late 2021 commercial satellite photos indicated that North Korea attempted to launch an SLBM from their lone submarine modified to do that. This was apparently successful. At the same time North Korea apparently completed construction of a 3,000-ton diesel-electric sub that can carry three SLBMs. Satellite photos show that this boat has not yet been used for a SLBM test. North Korea has Gorae (Whale), a smaller (1,500 ton) diesel-electric sub modified t0 include a single ballistic missile launch tube in the sail. This sub was used as early as 2016 for SLBM tests but most SLBM tests were still launched from an offshore underwater platform. North Korea used their smaller Gorae, which is one of a kind and used for the North Korean Polaris SLBM, a copy of the Russian Cold War R-27 but with a solid fuel motor. The Gorae is still in service and work continues on getting the SLBM to work reliably while the new 3,000-ton missile sub awaits any last-minute modifications from tests carried out using the smaller Gorae.
North Korea recently declared that it had changed its policy on the use of nuclear weapons and that from now on it would use its nuclear weapons without warning if it believed it was about to be attacked. This ominous declaration had more to do with the dismal shape of the North Korean nuclear weapons and the means to deliver them. North Korea has conducted six nuclear weapons tests between 2006 and 2017. The last one, in 2017, appeared to be the largest one yet indicating a yield of over 100 KT (equivalent to tons of conventional explosives or a kiloton) and described as a hydrogen bomb.
The first nuclear test was in 2006 (less than one KT) but the first one that was truly successful occurred in 2013 (6 KT) and despite the fact that the test was not a complete success, the nuclear bomb program continued with two tests in 2016. In late 2015 Kim Jong Un claimed that North Korea had developed a hydrogen (fusion) bomb. Foreign experts openly expressed skepticism given that North Korea didn’t really have a reliable fission type nuclear bomb yet. You need an efficient fission bomb to trigger the fusion reaction that makes the “H-Bomb” so much more destructive than a fission bomb of the same weight and size. Nuclear test number four in January 2016 was described by North Korea as a fusion (H-bomb) test when it clearly was not, or not a successful one. That would be in contrast to the 2013 test which appeared to be seven KT and a complete detonation. The second test was a two KT weapon in 2009. Western intelligence believed that the original North Korean nuclear weapon design was flawed, as the first two tests were only a fraction of what they should have been. The first one was less than a kiloton and called in the trade, a "fizzle." The second test was less of a fizzle and apparently a modified version of the original design. North Korea needed more tests to perfect their bomb design and was still years away from a useful nuclear weapon even though the second bomb appeared to be more effective. The third test in 2013 was considered overdue and that may have been because more time was spent designing and building a smaller device that could fit into a missile warhead. The second 2016 test is still something of a mystery. U.S. intelligence agencies have collected air samples (as have most other neighboring countries) from the test which can tell much about the design of the bomb. The January 2016 nuke appeared to be the same as the 2013 one. The second 2016 test in September appeared to be a better design and was about ten KT.
The 2017 test was the largest (in KT) yet and North Korea insisted it was a fusion bomb. Air samples were collected for weeks and it took even longer to analyze the samples and come to some useful conclusion. The sheer size of the 2017 test (100 kilotons) indicated either an enhanced (some fusion involved) fission bomb or a true fusion device (generally about 50/50 fission/fusion). Enhanced fission designs have been around and in use since the late 1940s, and fusion ones since the middle 1950s. After the Soviet Union collapsed in 1991 a lot of Russian nuclear weapons designers and technicians were out of a job and the pensions of the retired ones were suddenly worth a lot less. The security for nuclear weapons designs, especially much older ones, became a lot more relaxed. There were plenty of opportunities to obtain previously unavailable tech. North Korea's nuclear weapons development always had an air of desperation. North Korean Leader (since 2011) Kim Jong Un insisted reliable nukes and ballistic missiles to carry them were essential to keep his socialist dictatorship in power and capable of extorting food and other aid from South Korea, Japan and the United States. That is not working either as all three of these nations have increased their ABM (antiballistic missile) defenses and the number of offensive weapons for destroying North Korean nuclear weapons, delivery systems and military capability in general. All three of these target countries had tried, for years, to help North Korea with lots of food and economic aid but it was never enough for the Kim dynasty that had ruled the north since 1945. A decade ago, South Korea, the last nation offering aid to North Korea, gave up that approach and recognized North Korea as hostile and not likely to change as long as the Kims were in charge. North Korea is undergoing another cycle of mass hunger and starvation deaths brought on by so much of the North Korean economy dedicated to the nukes and ballistic missiles.