After nearly 15 years, the Taliban show no signs of slowing their insurgency in Afghanistan. Hopes that the group would participate in peace talks were recently dashed when it announced it would not, even though a small rival Islamist group, Hizb-i-Islami, agreed to be included. Afghanistan, China, Pakistan and the United States –- all part of the Quadrilateral Coordination Group for stabilizing Afghanistan -- ended their latest meeting in February on a cautiously optimistic note by formally inviting the Taliban to talks. But in early March, the militant organization released a statement saying it would decline the invitation until its demands are met. Then in an unexpected gesture on March 17, Mullah Akhtar Mansoor -- leader of the mainline Taliban faction who has been silent since allegedly being wounded in a gunfight in November -- released an online statement in Pashto exhorting the Taliban to intensify their fighting. This suggests...