Original sentence: Since the US War in of Afghanistan in response to the September 11, 2001 attacks in New York and Washington, many Al-Qaeda operatives were alleged to have snuck into Iran.The United States has expressed concern about Tehran possibly letting these prisoners leave Iran
Edited sentence: Since the US invasion of Afghanistan in response to the 9-11 attacks, many Al-Qaeda operatives have snuck into Iran.The United States has been concerned about Tehran possibly letting these prisoners leave Iran.Traditionally, Iran, a Shiite nation, had always been suspicious of the Sunni group