Why is the u. s still occupying afghanistan ?

Because U.S decided to maintain a force of 8,400 troops in 4 garrisons (Kabul, Kandahar, Bagram and Jalalabad) indefinitely due to Taliban resurgence attempt after the Battle of Kunduz.

Explanation:

The United States invasion of Afghanistan occurred after the September 11 attacks in late 2001, supported by close US allies. The conflict is also known as the US war in Afghanistan. Its public aims were to dismantle al-Qaeda, and to deny it a safe base of operations in Afghanistan by removing the Taliban from power.

United States of America and its allies successfully drove the Taliban from power in order to deny al-Qaeda a safe base of operations in Afghanistan.

me on my last question.