US Military officials are considering a significant change in the war command in Afghanistan to extend US control of forces into the country's volatile south. The idea is linked partly to an expectation of a fresh infusion of US combat troops in the south next year. Taliban resistance has stiffened in the south since NATO took command there in mid-2006, and some in the Bush administration believe the fight against the Taliban could be strengthened if the United States, whose span of control is now limited to eastern Afghanistan, were also in charge in part or all of the south. The internal discussions about expanding the US command role were described in recent Associated Press interviews with several senior defense officials who have direct knowledge but were not authorized to talk about it publicly. All said they thought it unlikely that a decision would come soon. Giving US commanders more control in the south would address one problem cited by U.S. officials: the NATO allies' practice of rotating commanders every nine months, and in some cases their fighting units every six months. The 101st Airborne, by comparison, is in eastern Afghanistan on a 15-month deployment. In the US view, nine-month commands are too short to maximize effectiveness.