The major military challenge that the United States faces today is the war in Afghanistan. The U.S. military is engaged in a grueling counterinsurgency campaign against the Islamist movement known as the Taliban, which is based among Pashtun tribes in Southeastern Afghanistan and Northwestern Pakistan, who have never been permanently subdued by a foreign military force. This challenge comes in the wake of that other grueling counterinsurgency war that the U.S. military has had to conduct in Iraq, where its chief adversary was the Islamist movement known as al Qaeda in Mesopotamia. Moreover, the challenge in Afghanistan comes on what could be the eve of an impending military challenge, perhaps even a war, with Iran, as that Islamist state relentlessly moves toward acquiring nuclear weapons. In its entire history of two- and-a-quarter centuries, the United States has never been engaged in an unbroken succession of three wars, in three different countries. Together, the U.S. wars with or within Islamist countries add up to what is a “long war,” indeed.