WASHINGTON, D.C.: Washington’s special envoy to Afghanistan and Pakistan stepped down on Friday, just as the United States is preparing to send thousands more troops to the region. A senior State Department official told Agence France-Presse that acting special representative Laurel Miller left the post without a replacement being named. State Department spokeswoman Heather Nauert said Miller is returning to a position at the Rand Corporation and that Secretary of State Rex Tillerson has not yet decided what to do with post. The office was created when US officials decided that the conflicts in Afghanistan and Pakistan are inextricably linked and ought to be dealt with together. Miller’s responsibilities will now fall under the department’s South and Central Asian Affairs Bureau, which has a much bigger footprint that includes India.