The collapse of the western backed government in Afghanistan is a shock. It has shaken confidence in democratic countries, and changed the balance of power somewhat, as between the United States and China.
It shows that efforts from the outside to topple regimes, and to replace them with friendlier ones are more difficult than anyone thought 20 years ago, when the western allies first overthrew the Taliban regime in the wake of 9/11. The aim of capturing Osama Bin Laden was not achieved until much later, and then it was achieved in Pakistan (an ostensible ally of the United States) , and not in Afghanistan at all.
The end of the US intervention in Afghanistan has lessons for those who might wish to undertake similar exercises in Somalia, Libya, Syria, Cuba, Mali or Venezuela. The objectives need to be clear and limited. Local support must be genuine. If one is seeking out terrorist suspects, invasion is not the best way of achieving extradition! Nation building is best done by locals.
Existing regimes may be oppressive or corrupt, but if they are home grown, and have developed organically from local roots, they survive better than anything , however enlightened, introduced from outside.
Conventional military power-boots on the ground and targeted bombing- is of limited effectiveness against networks of fanatics or mobile guerrillas.
Western countries will now need to reassess their military spending priorities in light of the lessons of the interventions in Iraq, Libya and now Afghanistan
On this occasion, it is the US and NATO that have the hardest lessons to learn, but I suspect that if China were to attempt a similar exercise in nation building from the outside (say in Taiwan) they would have the same experience.
The fact that China has had to adopt such extreme measures in Sinkiang to integrate that province into the Chinese social system is a sign of weakness rather than strength.
Afghanistan is an ethnically diverse society which, despite its diversity and disunity, has been able to resist rule from Britain, the USSR and, most recently, from the US and NATO. Religion was a unifying factor is an otherwise very divided country.
It seems the Taliban have been more effective in building an ethnically diverse coalition than was the former government in Kabul. It is not yet clear whether the Taliban will be able to hold that coalition together.
It does seem that the Taliban has, in the past, been able to impose a degree of order in Afghan society, and has been able to punish corruption. It created a form of order in a brutal and misogynistic way, but it did so. Order is something the outgoing government in Kabul could not provide, even with generous outside help.
Order, after all, is a prerequisite for any form of stable existence. Furthermore without order there can be no rule of law, and no democracy. Without iy, civil society breaks down. This applies in the West as much as it does in Central Asia.
Order is created by a combination of three essentials- loyalty, acquiescence and fear. All three elements are needed to some extent. Hamid Karzai could not command these three essentials, it remains to be seen whether the Taliban will do any better
It is hard to assess the effect the Afghan debacle will have on the United States, which has by far the most elaborate and expensive military forces in the world.
Will there be a change in US strategy?
There is a strong temptation to turn inwards and reduce commitments to the defence of other countries, including the defence of European countries. From 1783 until 1941 the US tended to remain neutral and rely on the oceans for protection against its enemies.
The countries of the European Union will also need to work out what their practical defence priorities are, in light of the Afghan and other recent experiences.. This is a political task of great difficulty because the 27 member states have very different views and geographic imperatives.