U.S. Troops Face Powerful Enemy on Afghan Border

U.S. forces have dramatically escalated their attacks across the border in Pakistan, where al Qaeda and the Taliban have had safe haven. On Tuesday, a CIA missile reportedly killed four militants in south Waziristan. That sets a new record, with 21 drone attacks this month.

CBS News Chief Foreign Affairs Correspondent Lara Logan reports that for American soldiers, the threat from Pakistan is constant.

"We have to move guys!" yelled a soldier.

The ambush was well-timed, hitting U.S. soldiers at the most vulnerable spot in a remote canyon a few miles from the Afghan border with Pakistan.

They made it out safely by running from rock to rock through the gunfire, but very often in this hostile border area they don't get so lucky.

More from Lara Logan on the war in Afghanistan:

60 Minutes: A Relentless Enemy
Fighters On Afghan Border: A Relentless Enemy
60 Minutes: The Taliban's Power

Their enemy is a mix of Afghans, al Qaeda and the Pakistani Taliban, the same group behind the attempted bombing in New York's Times Square last May.

CBS News spoke with Lt. Col. James Vowell about who his soldiers are fighting.

Lara Logan: "You're fighting Afghan Taliban, but you're also fighting Pakistani Taliban?"

Vowell: "Yes."

Vowell commands a forward operating base fewer than five miles from the Pakistani border.

Logan: "You lost eight soldiers in your first 30 days?"

Vowell: "That, unfortunately, woke us up from a deep sleep, I think. That's when we picked up on fact that there is a deliberate thought process from the Pakistani Taliban to go after us in a much more concerted, intense way."

Vowell says the fight may be in Afghanistan, but the war is being run from Pakistan.

Logan: "How powerful are those Taliban shadow governments that are operating from Pakistan?"

Vowell: They're effective enough to resource, train and get these soldiers - for jihad - to come across the border."

Logan: "They announce operations?"

Vowell: "Uh-huh."

Logan: "They help to finance, train and recruit?"

Vowell: "They have to. It doesn't come out of thin air."

Maj. Gen. John Campbell is Vowell's boss. What worries him as much as the border is losing support back home.

"If we lose the support of the American people and we have to come out of Afghanistan without completing this mission, then I think our country has failed," says Campbell.

Campbell has lost 59 of his soldiers since they arrived in Afghanistan eight months ago. The pressure to turn this war around lies heavily on his shoulders.