The U.S. has maintained a presence in Afghanistan for almost 20 years since the al Qaeda terrorist attacks of Sept. 11, 2001. Almost everyone is looking to see this chapter of American history come to a close, but history has proven the consequences of the U.S. pulling out of a country before the foundations of a decent political government were in place. If a military presence were absent, the Taliban could create a resurgence and wreck more havoc, undoing all the work military forces have brought in.
Source: https://thehill.com/opinion/international/476764-the-high-costs