Why did the USA and its allies invade Afghanistan in 2001 and why did they stay until now

Why did the USA and its allies invade Afghanistan in 2001 and why did they stay until now

this DRP IS WRITTEN BY A WRITER, BUT HE OR SHY PUT WRONG FOOTNOTES, AND WRONG STYLE OF FOOTNOTES, SO IT NEEDS TO BE CORRECTED, JUST CORRECT FOOTNOTES AND CHICAGO MANUAL STYLE FOR FOOTNOTES AND BIBLIOGRAPHY, ANY ONE INTERESTED WITH WELL KNOWLEDGE OF FOOTNOTING. PLEASE CHAT ME. I AM SENDING A COPY OF GUIDE OF FOOTNOTING ,PLEASE SEE PAGES NUMBER. 12-23-14 FOR FOOTNOTES AND PAGE 19 FOR BIBLIOGRAPHY, THANKS . AND AFTER AGREEMENT I WILL SEND THE ESSAY FOR CORRECTION.