On Sunday, another coalition soldier was fatally wounded. Afghan commanders say they are fighting Taliban and al-Qaida remnants who have safe zones in Pakistan and are able to cross easily into Kunar. They are also fighting followers of Gulbuddin Hekmatyar, a powerful warlord who has refused to join Afghanistan's nascent government.

There are also locals who once gave up their guns when economic development seemed likely but who are now picking up the fight again. Some U.S. officials say troop strength is enough in these areas but that more development will bring stability where soldiers cannot. Meanwhile, they continue to push north.

Last week, four U.S. soldiers were killed "while conducting security operations to interdict enemy movement through northern Nuristan," the province north of Kunar, according to a Pentagon statement.

Staff Sgt. Shawn Nedari, a National Guard adviser to the Afghan army who grew up in Manhattan and whose parents are Afghan, fought and patrolled in the mountains of Kunar during a recent coalition push into the area. Villagers told him that they would be unable to provide information without security.

"The problem is, we don't stay there long enough to keep the insurgents out," he says. "We don't have enough bodies." Brig. Gen. Zemari, who commands the brigade of the Afghan army operating in Kunar, has been wounded 15 times in battle and knows how hard it can be to fight insurgents in the mountains without the help of locals.

"The problem is not knowing, not having exact intelligence reports and no indication of the enemy from the people," he says. "Without intelligence, we cannot separate the enemy from the locals. So if we do something, we will bring damage to the locals, and the people will not get along with the army and will not be happy with the army."

Building schools, roads, and clinics is more important than putting more troops on the ground, Zemari says, a statement echoed by U.S. officials. "As the Afghan government builds the capacity to extend their reach, security will improve even more," coalition spokesman Paul Fitzpatrick wrote in an e-mail. "This is not about U.S. troop levels in Kunar or anywhere else. The solution lies within the Afghan government and its people."

Development, meanwhile, is practically impossible without security from insurgents who target aid efforts — not to mention the rugged terrain that has hindered progress even in years of peace.