Perhaps the only immutable with regards to human institutions is their underlying need to evolve. All human institutions change over time, and ultimately all particular social-political entities are terminal: all organizations of human beings are ultimately mortal. The geopolitical entities of the Korean peninsula are themselves certainly no exception to this rule. Over the many centuries during which the peninsula has been settled and civilized, it has found itself host to several different political regimes, sometimes unified, sometimes politically disunited. One of these political entities, Silla, managed to unite the Korean peninsula, for several hundred years. Eventually the Silla state began to decline, however, and lost control over the majority of its territory, leading to the eventual extinction of the Silla state. Of considerable interest is the matter of the factors which ultimately led to the dissolution of Unified Silla, the events and trends which coalesced to bring to an end the first political regime to unify the various peoples of Korea under a single banner.

Machiavelli felt that all states must ultimately collapse, if not from outside interference or from unpredictable calamity (the ills of Fortuna), then from natural internal degeneration of the state in question. Essential here is an understanding of what is meant by the term state. A state is a government, the individual or individuals, or bodies of individuals in whom the sovereignty over a people and a country/territory is vested. Therefore to say a state degenerates is to say that the individuals in whom political power is vested, regardless of how they came to be vested with that power, become incapable of effectively wielding power. Therefore the degeneration may originate from the adoption of ideologies, philosophies, and/or religions which are not viably applicable to statecraft. Just as likely, however, is the case of political inebriation. In this case the sovereigns become complacent and unresponsive, increasingly disinterested and incompetent with regards to matters of state. Political inebriation is ultimately the result of the sovereign(s) spending too much time enjoying the yields of their success and inadequate time concentrating on the maintenance and continued expansion of their particular power and stability. As Machiavelli states:

Thus, on the other hand, if Heaven be so benevolent
that it [a state] never has to wage war, the idleness would
result in making it either effeminate or divided; these two
things together, or each one in itself, would be the cause
of its ruin. ⁽¹⁾ Unified Silla is a prime example of just such a case.

In the case of Unified Silla, one finds a very successful state in which the central government, controlled by a king, has over time managed to consolidate considerable power, accumulating it in both the particular power of the throne and the administrators of the throne, the Confucian bureaucracy. The other major wellspring of power, the aristocracy, has become largely pacified through complex marriage arrangements and, more importantly, through the crown's assurance of their social and economic power. Fairly good relations exist between Silla and the other major powers of the region: Tang China, the early Japanese states, and the northern tribes. Trade is profuse, benefitting the throne through official tribute channels.⁽²⁾ Life was good in Korea during the height of Silla power, at least for the upper classes.⁽³⁾ An official Tang history of Silla records, "Emoluments flow unceasingly into the houses of the highest officials, who possess as many as 3,000 slaves, with corresponding numbers of weapons, cattle, horses, and pigs."⁽⁴⁾ Furthermore, Ki-baik Lee states, "It was also said that there was not a single thatched roof house within Kyngju's walls, while the never-ending sounds of music and song filled the streets night and day."⁽⁵⁾ The Silla had achieved success, and in such was their downfall.

After reaching the pinnacle of their power, the Silla kings and queens began to make the mistake of enjoying their power too much, of becoming too comfortable in their prosperity, too assured of their security.⁽⁶⁾ As they began to increasingly neglect their royal duties, the results gradually began to manifest themselves throughout society. The king's elite Buddhist military, the Hwarang-do, the basis of his power, began to lose discipline, both ideologically and militarily, largely because of the lack of any visible enemy, either internally or externally.⁽⁷⁾ Furthermore, within the capital the Old Aristocracy had not forgotten their roots, indeed, they had not only not forgotten that it was they, their families, who once held the power in Silla, but they still aspired to hold that power and the honor and wealth that accompanies great power.⁽⁸⁾

This is not to say that the kings and queens of Silla turned a completely blind eye to the growing cracks in their power, indeed, there were numerous attempts to reform, to reinforce their reign. However the attempts were mostly half-hearted, like mottle on the leaks of a collapsing dike.⁽⁹⁾ Efforts by the Confucian bureaucracy, made up mainly of members of the Sixth-Head rank and therefore rivals of the Old Aristocrats attempting to regain power, tried to stem the tide but were largely hogtied due to the lack of royal will.⁽¹⁰⁾ Also, because of the restraints of the Bone-Rank system the bureaucrats, the basis of royal power, found it virtually impossible to achieve rank, honor, wealth, or reward worthy of the skill or amount of work they were responsible for. Many of these bureaucrats simply retired to the countryside, while some went west to Tang China, seeking to serve in what they perceived as a benevolent government, and some, free of the constraints of the capital, began to accumulate increasing power which they dedicated to the advance of their own interests rather than that of the central state.⁽¹¹⁾ By the time the Old Aristocracy had regained primacy in the capital, the countryside was full of 'Castle Lords': individuals of True Bone Rank, Sixth-Head Rank, and lower social ranks who, fed up with their inability to achieve success in the politics of the capital, began to seek success in the political vacuum of the countryside.⁽¹²⁾ And a vacuum it was, almost entirely neglected by a capital consumed by its own internal divisions and revels.

If one were to call the situation of the capital that had arisen during the fading of the crown's power and the recession of the bureaucracy chaos, then perhaps one would describe the situation after the Old Aristocracy had regained their lost power and influence as pandemonium. During the first period aristocratic domination of Silla, before a goodly amount of centralization had occurred, the Old Aristocrats of the Holy Bone and True Bone ranks had maintained their power through a system of discipline and self-restraint, knowing that their power rested on their mutual cooperation and success (e pluribus unum, if you will). Yet this new incarnation of Old Aristocracy power had never experienced this former system and largely lacked the social infrastructure to implement the former system.⁽¹³⁾

And surely one cannot underestimate the importance of the fact that this Old Aristocracy had experienced a true and viable kingship, had seen what they could be, what could have, if only they were able to steal for themselves the power of the throne. And so, the Old Aristocrats began a phenomenal power struggle, abandoning cooperation in hopes of achieving personal domination. Silla's center had become rotten, and she found herself deprived of any useful monarch or aristocracy, void of any real political unity or coherence.⁽¹⁴⁾

The time was right for the rise of a New Aristocracy, the already mentioned Castle Lords. These men began to increasingly exert influence over particular areas, gradually elevating themselves to the role of localized lordships, families who held authority over large numbers of people and considerable tracts of land. The development of the New Aristocracy had multiple consequences, all of which increased the likelihood that the Silla would dissolve. For one, by acquiring authority they took power from the central entity, and by holding that authority (and apparently the recognition of the commoners over whom they held sway) they developed legitimacy, legitimacy which was effectively removed from the center. Their legitimacy and authority were further reinforced by their undertaking activities which are explicitly reserved for the states: they began to raise standing military units and to levy taxes.⁽¹⁵⁾

With its military effectively devolved and its bureaucracy largely disbanded or wholesale integrated into the mechanisms of the New Aristocracy, the center was at a loss for recourse. Indeed, despite the fact that the Old Aristocracy factionalism began to be put aside in an effort to reinforce their power, the center was unable to halt the flow of power to the countryside. In addition, as money and labor began to flow away from the capital, endangering the mode of living to which the Old Aristocracy had become accustomed to, the Old Aristocracy reacted by levying increased taxes. This double taxation of the masses led to a dramatic decline in the living standards of the common people, from sustenance to starvation.⁽¹⁶⁾ "In an attempt to overcome its financial crisis," states Ki-baik Lee:

the government in 889 resorted to forced collection of
taxes from the provincial and county areas. But this
resulted in a dual burden being imposed on the peasant
population, for they now had to suffer not only from the
exactions of the castle lords under whom they lived but
from the levies of the central government as well.⁽¹⁷⁾

"Now," states Lee, "the government's last gasp effort to fill its treasury by force drove the peasantry into seething rebellion."⁽¹⁸⁾

Interestingly, the peasant revolts seem to have occurred primarily in areas which were not in the pre-unification Silla domain. Furthermore, as the peasant revolts began to coagulate around leaders, forming into full-scale rebellion, they not only fell upon the same general geographic lines as their predecessors, but took on the same symbols of state, declaring the Later Kogory in the north (led by a Castle Lord who claimed to be the son of a concubine of one the Silla kings), and the Later Paekch in the southwest (founded by a 'robber-thief' who had gained position and honor in the Silla court defending against the onslaught of the Later Kogory, then disillusioned and traitorous, used his status to gain control of the southwestern rebellions). This all implies the existence of latent identification with earlier geopolitical entities, probably centered along cultural and linguistic lines. The Silla now had to contend with organized states motivated by historical consciousness and cultural/nationalistic urges, states led by charismatic individuals with motivated and hardened troops.⁽¹⁹⁾

The Silla were further damned by two other developments to which they were either completely unresponsive or inadequately so. Among these was the rise of free artisans and merchants. These individuals dramatically improved their own economic positions as the Silla progressed, first through catering to the center and later by catering to the New Aristocracy. The Silla's mistakes with regards to this rising class were simple: they restricted their ability to acquire capital and use it to their own benefit (which would have provided motivation to improve the economy even more dramatically) and they neglected to develop a tax structure which would have complemented a rising merchant/artisan class, providing a source of income that would have decreased the center's dependency on the peasant class.

Yet another development which likely sped the Silla's demise was the changing nature of the international system, a system which had earlier been extremely supportive of the Silla regime. Essentially, the one development which fundamentally altered the East Asian world-system was the collapse of the Tang. Why would this have endangered the Silla system? Simply put, the Silla had numerous links to the Tang Empire, economic, political, and otherwise. Not the least of these connections was the traditional 'tribute system' of China, which was largely a high level form of trade. With the collapse of the Tang, the Silla center would have lost a massive source of revenue, the loss of which may have, again, incited the upper classes to increase taxes, resulting in the peasant revolts of the same time.⁽²⁰⁾ Furthermore, the collapse of a political regime always results in a general downturn in the overall economic prosperity of a system, perhaps resulting in an overall decrease in the fortunes of those parts of Unified Silla most likely to be dependent on trade with Tang: the north and southwest Silla, those same regions where the revolts first occurred.

As one reviews the various happenings and transpirings which, more likely than not, converged to result in the ultimate demise of the Silla, one begins to develop an understanding of true complexity behind the collapse of a regime. In the case of Silla we find a divided upperclass which, as time progresses, becomes even more divided. If this condition were not pitiable enough, then we simultaneously find the gradual moral and disciplinary decline of these same elites, a regression from a state of propriety and moderation into one of unresponsive, unprepared, total self-interest, so much so that they lack even the ability to maintain the system in a manner that continues to serve their particular interests. In the countryside new elites, a New Aristocracy was rising, one forged from work and political harangues, an elite up to the task of power politics. The peasantry is crushed between the demands of the old behemoth and the powerful new hatchlings, pushed and pushed into ever deeper economic despair until finally, unable to withstand further insult and depredation, they rise up in revolt. In the midst of this chaos the New Aristocracy, their political and military skills honed, raised old banners, calling upon ancient loyalties to achieve new goals. Being both motivated and skilled in the arts of politics, these new leaders utilize the fires of the revolt to forge to new, viable states, one of which, Kory, ultimately is successful in reunifying the peninsula, ending the Silla finally and forever. And thus in the Silla we see not only the particular collapse of a single political entity, but also several of the common defects which may lead to the collapse of any political entity.