Why America’s longest and most expensive war in history failed: analysis

TEHRAN - On the third anniversary of the U.S. exit from Afghanistan, three writers - Michael A. Cohen, a nonresident senior fellow at the Center for Strategic Studies at the Fletcher School of Law and Diplomacy at Tufts University; Christopher Preble, also from the Fletcher School and senior fellow and director of the Stimson Center’s Reimagining U.S. Grand Strategy Program; and Monica Duffy Toft, an academic dean and professor of international politics at the Fletcher School and Director of its Center for Strategic Studies - analyzed the failure of the U.S. war against Taliban after 20 years.