Strategypage looks at North Korea. The North Korean army is viewed by the regime as a threat that is kept around basically for slave labor lest young men in prime fighting age turn against the regime in their spare time:
Since 2010 the North Korean military has been quite obviously in bad shape. This was the result of two decades of shrinking budgets, reduced training and little new equipment. The only big changes have been a reorganization of the reserves (disbanding many divisions and transferring their equipment to active duty units that needed it more) and expanding the "Special Forces", which are now 16 percent of all troops and apparently the only ones the government feels it can depend on. Since 2010 Special Forces have been expanded to at least 180,000 troops. Keeping the armed forces loyal is apparently the main function of the North Korean Special Forces, not leading another invasion of the south. The Special Forces are largely light infantry trained and equipped for sneaking through South Korean front lines and cause trouble. Some of these troops have complained of food shortages so it is imperative that the Special Forces get special treatment. But now the government obviously can’t keep the Special Forces well fed.
For a while, the regime thought it could afford to gut the regular army and use scarce money to build nukes to deter invasion and to supply the most loyal security apparatus to maintain the regime against the people and army. Even that kooks, spooks, and nukes strategy is failing as even the special forces (not like our SEALs or Delta Force in quality, I should add, mostly just good light irregular infantry) are short of support.
Actually, one worry I have is that Kim Jong-Un might start a conventional war for the sole purpose of having South Korea and America kill North Korea's army, assuming that the allies would be content to defeat an invasion attempt rather than follow up with a counter-attack north of the DMZ.
That outcome would leave Kim in charge without the threatening army around but able to blame America and South Korea for the destruction of the army. That logic might be all kinds of way wrong, but Kim might believe it would work--or that is has the best bad chance of working out of a lot of worse options.
There is more in the Strategypage link, including signs of the people losing their fear of the regime, so you should read it all.
And this is highly interesting:
China has banned all Chinese tourists from the North Korean capital. This leaves only day trips to the North Korea border town of Sinuiju, which is just opposite Dandong, a Chinese city where most Chinese tourists depart from.
This deprives North Korea of money, but it is significant in that Chinese tourists could be more rapidly pulled out of North Korea should China want to stage an invasion-supported coup to end the North Korean nuclear threat.
And while the North Korean nuclear threat is mainly to South Korea, Japan, and America, North Korea with nukes might think it can defy China more rather than bend the knee as a client state.
Worse, North Korean nukes could start a wave of nuclear states in the region that are more basically hostile to Chinese attempts to control them:
A South Korean ruling party lawmaker said he is in favor of the redeployment of tactical nuclear weapons in his country, although South Korean President Moon Jae-in's office clearly ruled out the option in September.
Lee Jong-kul, a politician in Moon's progressive Minjoo Party, said Tuesday he is seeking U.S. endorsement on a potential South Korean decision to develop and deploy "sophisticated nuclear assets" on the peninsula to deter against North Korea provocations.
"Tactical" nukes are really just short-range nukes and if aimed at a city will do considerable damage even if you need multiple warheads to create the damage of a larger "strategic" nuclear weapon. China is close to South Korea.
And to Taiwan, Japan, and Vietnam. So North Korea is China's problem, too.
