There are many reasons why the North Korean armed forces, despite its large size (about a million troops) is considered ineffective. One of the least talked about (in the media) problem is the growing use of bribes within the North Korean armed forces. This begins when young men are conscripted. The growing wealth generated by the legalized market economy in the north means there are more middle-class families and officials with lots more cash because of the opportunities for extracting bribes from this new and growing entrepreneurial class. Thus it is now common for conscription officials to accept bribes to get the sons of affluent families into choice jobs in the capital, the internal security service, anywhere but the combat divisions on the DMZ (Demilitarized Zone that separates north and south). This type of bribery has become so widespread that jobs in the bureaucracy and military dealing with assignments of new conscripts (and thus the people to be bribed) are now being sold to officers who have the most cash. Buying one of these jobs is a good investment, because a lot of money can be made. There is some risk because of occasional crackdowns. If you get caught life in a labor camp or executed is likely. But so far the risks appear to be low and the money is good. It’s gotten to the point where if you pay a large enough bribe to the right people you can be out of the military within six months with a medical discharge.
Meanwhile the Inmun Gun (the North Korean armed forces) has its lots of other, and older, problems. While nearly every adult male serves at least six years in the military up there the big problem is that years of economic problems and failed harvests have left the troops poorly equipped, often hungry and increasingly insubordinate. With most of the best educated troops bribing their way into any job but one in a combat unit it is increasingly doubtful if the North Korean combat forces could get very far during an invasion of South Korea. Despite all that a lot of North Korean troops are believed to be reliable enough to carry out orders to invade South Korea, for a while at least, and that could end up doing a lot of damage to Seoul (the southern capital where half the population and a quarter of the GDP are). South Koreans have more to lose than the northerners. Sprawling Seoul is 40-50 kilometers from the North Korean border. The city alone is 600 square kilometers, and the suburbs are even larger. There are over 17,000 people per square kilometer (45,000 per square mile) in the city. The southerners know the north is desperate and heavily armed. What do you do? South Korea has responded by increasing its ability to quickly halt any rocket and artillery bombardment from the north. This would involve a lot of artillery and smart bomb use in a short time. Many North Korean targets would be destroyed but the south has much more to lose, even if the northern attack is cut short.
The North Korean Army has about 800,000 troops, over 3,000 tanks, 3,000 other AFV, nearly 8,000 artillery pieces (including 2,000 rocket launchers) and most of them are aimed south and stationed on or near the DMZ. Thus North Korea has the means to be dangerous, for a little while anyway. Fuel shortages, elderly equipment and lack of maintenance means that a lot of this gear would not stay operational for long. North Korea has two armored divisions, 12 motorized infantry and 23 "leg" infantry divisions (for occupying the DMZ positions).
Most of the best educated troops are in the rear areas, where their parents, bribes and instinct for self-preservation put them. The troops along the DMZ know this and are expected to lose some of their enthusiasm as a result. A growing number of North Korean refugees arriving in South Korea, who served along the northern side of the DMZ, confirm all this. They also confirm that the growing culture of corruption in the military leadership and bureaucracy is seeing more and more of the food and fuel meant for front line troops diverted by corrupt officers and sold in the markets. No wonder so many parents are willing pay bribes to make sure their kids never get assigned to one of those units.