Tens of thousands of fresh American troops are now on the move in Afghanistan. FRONTLINE producers Martin Smith and Marcela Gaviria, through interviews with the top U.S. commanders on the ground, embeds with U.S. forces, and fresh reporting from Washington, they examine U.S. counter-insurgency strategy in Afghanistan and Pakistan - a fight that promises to be longer and more costly than most Americans understand.

- This program contains graphic language and imagery. Viewer discretion is advised.