Now or never! This seems to be the stance taken by the Taliban on seeing the American troops withdrawing from Afghanistan. It looks as though it was well planned earlier. Very well earlier! Otherwise, they could not taken the whole of Afghanistan at such a short period, without much resistance.
Actually, President Trump had the ball rolling on February 2020, in Doha, Qatar, when a peace deal and agreement on troop withdrawal was made with the Taliban. And, remember, the Taliban had insisted on a deadline of withdrawal by May 1, 2021. And President Trump did begin to withdraw the troops. Not all troops were withdrawn by May 2021. But credit to him, from 13,000, the number of troops remaining at the time of Biden was were 2,500. When President Joe Biden came into office, and later said he was withdrawing all the troops from Afghanistan, the media was wrongly accrediting him with the move – the decision to pull out the troops. That was Trump's triumph. Anyway, the Taliban were already well prepared since then,and were certain the final troop withdrawal was going to happen, and were waiting for it!
Poor Biden may have thought the Taliban will make some war moves in the way of conflicts and combats with the Afghanistan military. And American will, graciously, dispatch diplomats to mediate in the matter. But that was not to be. Biden did not realize that the Taliban would have, surely, thought of all these possibilities. And also failed to recognize that the Taliban would not have any of these. That was why he pulled the troops as he did, unintentionally, unknowingly but alarmingly, making the American supporters in Afghanistan running helter skelter, trying to get to the airport and leave their beloved land!
So there you are. Taliban are in full control of Afghanistan now. Only time will tell if this is for good or otherwise.