Therefore, the only option of peace is to partition and annex Afghanistan among Pakistan, Iran, Uzbekistan and Tajikistan along ethnic lines.
That is an excellent idea. Here is why...
Nation. A group of people that shares some common bonds, such as language, customs, and even racial characteristics.
State. A governing body over a people.
Country. A geographical locale.
For example: World Jewry was a people but with no state and no geographical area to call their own until the establishment of the state of Israel. And there are still plenty of 'stateless' peoples like the Romani (Gypsies) in Europe.
The word 'country' is used interchangeably with 'state' but can also be used to describe a region. Africa is a 'country' that contains many 'states'. Same with Europe and the Americas. So whenever we use the word 'country' we are describing a union of all three concepts.
So in the event where there is a breakdown or when there is not a long term cohesion of all three components, we really have no 'country' in popular language. The best word is simply 'country' in the most basic context: a geographical locale.
This is not radical. Taiwan is
de facto an independent country in the fullest context of 'country' despite having common ancestral ties with mainland China. The Korean peninsula is a 'country' with two politically distinct states, North Korea and South Korea. So at least an administrative partition of Afghanistan is definitely doable and I would argue desirable for the many peoples in that region.
A major concern is responsibility. An administrative partition among ethnic lines would burden the various governments with final responsibility on what goes on inside their respective regions. Al-Qaeda flourished in Afghanistan because of no central government. No
REAL central government. If any version or offshoot branch of Al-Qaeda or IS lives and breathes inside a region and wages jihad externally, that government will bear the brunt of retaliation.