The list of failures in Afghanistan is shorter than successes, every empire that invaded it up to the modern era succeeded. It is rough mountains land so power is decentralized an it takes a concerted effort over time to conquer all the tribes, getting them on side or making them part of the power base like the Persians did in establishing their Satrapies, Alexander did by marrying Roxanne and settling intermarrying his soldiers up to the Mongols that led to the existence of the current Hazarra minority.
The British, Soviets, and US have failed to 'conquer' or pacify Afghanistan though all with caveats. The British failed at conquering the whole of Afghanistan but did succeed at conquered what they considered strategically important and worth conquering ie the Khyber pass and Peshawar. The British and Russians essentially 'created' Afghanistan by drawing lines around what they would both agree not to conquer, it certainly wasn't a unified political concept before.
The Soviets invaded in the middle of a civil war, the extreme policies of Amin after he took over Afghanistan put it into a state of general revolt. The Soviets wanted to impose a more moderate communism on Afghanistan but Amin had already done his damage. Not that the Soviets would have succeeded, outside intervention into a civil war tends to go poorly, especially when the intervention is to take over one side instead of help it.
The US failure can be termed in failing to stop support for the Taliban and failure in stopping the tacet Pakistan support for the Taliban throughout the war. The biggest failure on the US side though has been I think by injecting too much money and material to the Afghan government which has made it incredibly corrupt and by not engaging the countryside. A conservative rural society can't be won over by securing the cities and major highways and building the Afghan Army as only capable of manning checkpoints instead of conducting effective counter insurgency. The failures in Afghanistan parallel a lot of the Nationalist failures in China and South Vietnam's failures too. Both those nations were famously corrupt and inept, letting Afghanistan become corrupt and inept and just accepting it because 'when it Rome' was stupid. Having the equipment to fight and win regular battles but not doing the reforms and engagement necessary to win over the majority rural population will not win a civil war. The US failure has been a failure to win the important battlefield which was the buy-in from rural Afghanistan for the new government. In hind-sight it should have remained a special forces war from the overthrow of the Taliban on, with the US focused on defeating Taliban and Al-Queda, not providing security and governing, with a return of the King for adding some legitimacy to the tribal leaders.
The current Afghan government has the capability to win, but just holding onto the provincial capitals, Kabul, and the highways is not the way how. US and probable Chinese investment may keep the current government from falling but I don't see them winning a civil war soon. The Taliban have to fail at governing and splinter before that could happen and Pakistan would have to stop trying to prevent a united Afghanistan behind them.
Bookmarks