Challenge: Military government as a Korean norm

The Kamakura Shogunate was about the same time as the Choe (or Choi) family of military dictators in Korea during the Koryo Dynasty. However, while the Choe regime was wiped out during the Mongol invasions, the Kamakura Shogunate survived, to be followed by other shogunates such as the Ashikaga Shogunate or the Tokugawa Shogunate.

However, with a point of divergence after 1196, when Choe Chung-heon became the first of the Choe family to rule Koryo, how would it look like if Korean history looked more like Japan? As in, could we see a succession of military dictators who rule the country on behalf of the Kings of Koryo (or perhaps another dynasty as well, if necessary), or was the Koryo military dictatorship a one-time fluke? In this challenge, with a point of divergence that predates the unification of the Mongols, the Mongol invasions might not happen. I think it might be more interesting to see Koryo resist the Mongols successfully, but I don't think this is likely, so the challenge would be easier if the Mongols never come to power.

Either way, how would Korea look with a series of bakufu governments as opposed to the scholarly bureaucracy historically?

Well, the first military dictatorship after the Mongol invasions was the one led by Yi Seonggye, who realized that keeping figureheads on the throne would probably reduce his influence, and just founded another dynasty.

That being said, another state would probably invade if the Mongols did not do so, and unless they were pushed out decisively in order to convince the public that the military had a key role in doing so, another set of monarchs would probably just take their place. However, if the military dictatorship had held on for at least a few more centuries, Korea might focus on expanding into Manchuria more than it did in OTL if the Jin dynasty fell apart, and it might have better success repelling the Japanese invasions if they invaded around the late 16th century.

Well, it's been not yet a month, so I can bump this.

So, let's say that in this world, the Mongols are butterflied away. The Jurchen Jin remain too strong, for now, for Koryo to take Manchuria. How does Korea look like under a sustained Choe dictatorship? For the sake of similarities, let's say it lasts from the 1300s, when the Kamakura Shogunate fell historically. Like Japan, would there be an attempt to destroy the military dictatorship, and what predictable factors would result in its success of failures?

Well, there are a few possibilities, and it's almost impossible to predict what would happen several centuries after the POD, so I'll try to focus on the short term.

The issue with Goryeo, or with any Korean dynasty, retaining military dictatorships with puppet rulers for a significantly long period of time is that there was no clear precedent at all for most of its history. In fact, even though Gung Ye founded what would later become Goryeo, he was eventually overthrown by the general Wang Geon because the ruler began acting erratically, and the soldiers thought that it would be a liability for him to remain in power. A few centuries later, in 1170, the situation had greatly changed, as the ruler and his officials began to make occasional trips to the countryside instead of focusing on how to govern the populace. As a result, several generals gathered together and overthrew the government in a coup, replacing the ruler with his younger brother. This led to several generations of rulers arbitrarily deposed and established by numerous military leaders, not to mention that Yi Ui Min was eventually assassinated and the establishment overthrown in 1196 by Choe Chung Heon, another general, because the latter thought that the military dictatorship had become too corrupt.

In other words, there are two main issues concerning why Goryeo's military dictatorship cannot last for more than 200 years or so. Too many puppet rulers were ousted for the military to retain them in the long term, making it more likely that a general like Yi Seonggye would eventually establish his own dynasty. If this scenario does not occur, a ruler could take advantage of the infighting between generals to outmaneuver them and reestablish Goryeo under a stable monarchy. Of course, it is possible for several military dictatorships to be retained for about 4-500 years, but I think it would be highly unlikely given the general instability of the military leadership and the monarchy itself.