The British fought in Afghanistan throughout the Nineteenth Century to safeguard the British Raj of India and left, determined to never mention that country's name ever again.
The Soviet Union invaded Afghanistan in 1979 to prop up a failing Communist government and ten years later withdrew without even looking over their shoulders.
Then it was time for the United States, perhaps having the best justification for invading after the 9/11 attacks, to plunge into the graveyard of empires in pursuit of Osama Bib Laden.
The original plan was to go in with about 30,000 troops, overthrow the Taliban and get Bin Laden, If the Bin Laden hunt did not workout, the regular soldiers would be pulled out in about six months and then Special Forces would continue the hunt and the Afghan people would not even know they were there.
Instead, the US has spent two decades chasing shadows trying to create a "new" Afghanistan.
The US had the perfect excuse to leave on May 1, 2011 when Bin Laden was finally killed. The United States could have been the first country to invade and leave under something like good circumstances. As usual, "mission creep" made its way into and everything went off the rails.
Ten years after the perfect reason to leave--and accomplishment of the primary mission--the US was supposed to finally leave. An agreement had been reached with the Taliban and we would see if the new Afghan Army would hold off the Taliban or would it perform an imitation of ARVN collapsing in 1975.
Then pushed the withdrawal date to September 11, 2021. In other words, every US solider in the country just became a target for an angry Taliban thinking the Americans would be gone. And what are those soldiers putting their lives on the line for now?
PR?
May 1 and the anniversary of Bin Laden's death would have worked better.
With out exceptionally poor quality of leadership, I shudder to think of what other missteps they will take.