ISIS

With the Islamic State largely defeated in Iraq, the country could move on to better governance and peace. However, it could just as easily repeat the mistakes of the past and lead to a resurgence of al-Qaeda or the birth of yet another extremist movement.

In his 2016 book The New Arab Wars: Uprisings and Anarchy in the Middle East, George Washington University political-science professor Marc Lynch notes, "This book has been painful to write" (p. 255).