From Nicholas R. Morrow, The Cipher Brief: “The Afghanistan and Pakistan region is home to 20 UN and U.S. designated terrorist organizations, including al Qaeda, the Islamic State (ISIS), and the Haqqani network. This is a higher concentration than any other region of the world, and it is why preventing Afghanistan from becoming a safe haven from which these groups can plan attacks needs to be a priority for U.S. President Donald Trump.”
From Robert Cassidy, RealClearDefense: "The main reason why we are still in Afghanistan after fifteen-plus years lies in the title. The sanctuary in Pakistan is the single most significant strategic impediment to stability in both Afghanistan and Pakistan. Almost every U.S. DOD report on progress in Afghanistan since 2008 explicitly states that Pakistan’s sanctuary and support prevent the defeat of the Taliban. The reduction of this sanctuary and stopping the sources of support of the Taliban in Pakistan is a strategic imperative to ending the war in Afghanistan with modest success. Pakistan’s failure to alter its strategic calculus, its incubation, and regeneration of murderous Islamist zealots, continues to pose a grave strategic risk for the war in Afghanistan. "
Pakistan, often in the headlines for terrorism, coups and poverty, has developed something else in recent years: a burgeoning middle class that is fueling economic growth and bolstering a fragile democracy. – Wall Street Journal (subscription required)