4,000 American troops , 650 Afghans involved in Operation Khanjar . At least 25 U.S. and British troops have been killed there in 2009 . Comment: Operation 's size and scope are `` very significant , '' official says .
4,000 American troops , 650 Afghans involved in Operation Khanjar . Comment: Operation 's size and scope are `` very significant , '' official says .