Mission accomplished? That was doubtless then-President Barack Obama’s expectation as he anxiously watched a team of American Navy SEALs kill al-Qaida’s leader, Osama bin Laden, six years ago. It was clearly Iraqi Prime Minister Haider al-Abadi’s hope last month when he visited the city of Mosul, newly liberated from the self-proclaimed Islamic State. But consider this: Al-Qaida had some 400 combatants on Sept. 11, 2001. Today it is stronger than ever, with several thousand adherents in countries from the Arabian Peninsula to Southeast Asia. If Western powers like the United States and the United Kingdom and their regional partners like […]