Why did the US and its allies invade Afghanistan and overthrow its government?

Question

A.
It was believed that Afghanistan’s army had been a part of the September 11th terrorist attack.
B.
It was believed that Afghanistan was harboring key members responsible for the September 11th terrorist attacks.
C.
Afghanistan was planning to attack Kuwait.
D.
Afghanistan’s government was planning to set up terrorist groups in the United States.

Answer 1

B. It was believed that Afghanistan was harboring key members responsible for the September 11th terrorist attacks.

The U.S. and its allies invaded Afghanistan in late 2001 primarily because the Taliban regime was providing sanctuary to al-Qaeda, the terrorist group responsible for the September 11 attacks. The aim was to dismantle al-Qaeda's operations and remove the Taliban from power to prevent further terrorism.