Nations are formed around contracts. It is rare for any nation to survive a change from the fundamental contract that it was founded on. And the common thread that runs for all the countries in the world at the current time, including a North Korea, is that they’re all part of a larger, interconnected, world. A world that is highly dependent on trade and commerce with each other for their survival.
This means that it is going to be impossible for any country, including an Afghanistan, to completely disconnect with the rest of the world. It is also instructive not note that no country has, in recent decades, gained considerable swathes of habitable territory in recent times, making any notion of a grand larger nation (often one that is drawn from a period in the distant past) an impossibility.
Thus, growth and prosperity in this era is going to be internal. It is the same reason why a China looks to increase its influence by means of easier or privileged access to other markets over claiming actual usable territory. Those markets feed the engine that urbanizes China as a country. Our era has little use for territorial dominance that does not provide market access. And where market access is possible without territorial dominance, the latter is an abject liability, and makes you a huge target in those territories.
When you violate the formative contract for a country, you compromise one of the key factors that enable prosperity and wealth creation for it, which is stability. This is particularly problematic for countries that are relatively young, with heterogeneous populations. The ideals, agreed to up on during the formation, is what it keeps it together. Change it, and you break the contract.
The contract is the thing that holds the country together. It provides a clear cost-benefit analysis and the give-and-take involved. When you unilaterally change it, you change the incentives for all the players. Countries are multiple parties that understand clearly their incentives in a collective. The sum of the parts is the nation, but the nation cannot exist without a significant number of the parts.