huàn zài tǔ bēng, bú zài wǎ jiě 患在土崩，不在瓦解
Calamity Is Collapse Like a Landslide, Not a Few Roof-tiles Coming Loose.
Disaster for a state is the collapse of its political power base, not the disintegration of its upper ruling stratum. The foundation of state power is popular allegiance and control of grass-roots society. “Collapse like a landslide” is a metaphor for political authority losing popular support, all of society crumbling precipitously and the people being driven to desperation and revolt. “Roof-tiles coming loose” refers to disintegration and splits in the ruling group, some struggling for power and others breaking the law and even plotting rebellion. Collapse means shaking the social and economic foundations of state power and denying its legitimacy and right to exist. It is thus something much to be feared. Disintegration, on the other hand, can usually be overcome within the existing framework and is not to be feared as much. This kind of political wisdom attaches great importance to the will of the people and governing grass-roots society. It is similar to the idea of “the people first.”
The greatest calamity for the empire is a collapse like a landslide, not a few roof-tiles coming loose. So it has been in the past as well as the present… If the empire is really about to collapse, even commoners and the poor will sometimes turn to evil and endanger the country. Chen Sheng was such a man… Although there may not be great order in the empire, as long as it is not actually about to collapse, it will be steadfast and not be conquered even when facing powerful states and strong troops. Wu, Chu, Qi, and Zhao were such states. (Records of the Historian)