Long ago, the nature of Afghanistan was that it was along a trading route....the 'Silk Road', and people came through....watered-up, got fed....then proceeded on. Traders had a 'road-map' and Afghanistan was simply a stop-off point. It's a 18-day venture across the middle of the country.....if you were doing twelve hours a day.
Lets also be honest and admit that it has been a tribal nation since day one, and remains mostly a tribal nation today. Some might argue that the past fifty years has changed things, but the majority of residents live in a tribal mentality.
There are a minimum of ten ethnic groups....of which the Pushtuns make up around 40 to 45 percent of the population.
The modern era? There are three British-India-Afghan wars....the first starting in the 1839 (going to 1842). The general fight over? It's generally discussed that the Tsar folks from Russia had come into Afghanistan....stirred up tribal units, and the Brit-India folks got reactionary. When the assumed leader of Afghanistan died in 1839, a follow-on leader became bogged down. In simple terms, a civil war erupted and the Afghans lost heavily but got the Brit-India folks to agree on leaving.
Around 1878, a second war occurred....same game (Russians, Brits, Indidans, and Afghans). This war lasted until 1880.
The 100-odd day war in 1919? This was going by the same script.....getting any British influence out of the country. The final result was that Afghanistan was recognized as a independent country, with no outside influence.
In the summer period of 1926, Afghanistan installed a 'king' and moved toward a 50-year period of stability.
In the summer of 1973....the King was kicked out and the country evolved into a 'republic'. Some will argue over this five-year period that followed, and that a lot of outside influence arrived, with a 1978 coup occurring, and a socialist Afghanistan state then existing.
This peaceful era of the new state? It basically lasted around 18 months. Pro-Islam groups gathered up, and a new civil war started. The state would have fallen....except the Soviets decided in December of 1979....to enter the conflict (staying for nine years).
The pro-Islam state that came after the Soviets left? It marginally existed because of continual conflicts with the warlords of various tribal districts.
If 9-11 had never occurred.....a continual civil war would be going on for the past twenty years and the two groups still fighting each other.
Afghanistan has never seen much of anything....except for conflict, and outsiders barging into the middle of a mess. The new Islamic Emirate? You can start the clock to ticking....this probably has no more than three to five years before they fall into some revolution and some new warlord rises to be 'supreme-leader'. Then some third generation Taliban crew will arrive and restart the clock to ticking once again.