It's the middle of the night at the east corner guard post of Fiddler's Green, a Marine fire base in Afghanistan's Helmand Province, along the border with Pakistan.

Corporal Ryan Joseph Bernal is on perimeter security duty.

Armed with an M-4, night vision binoculars and an array of high-powered automatic weaponry, the 22-year-old U.S. Marine and several others keep watch for activity just outside the concertina wire, which conveys the powerful message “DO NOT ENTER” in a universal language Marines, civilians and the Taliban all understand.

• Click here for photos.

Behind the sentries are the 3rd Battalion, 11th Marines, out of 29 Palms, California. They are relatively safe, and mostly sleeping.

As the American military's summer offensive into Taliban territory gains strength, the number of U.S. soldiers who have been wounded or killed in action has increased. But just as disturbing for these Marines is a new concern: the recent security breach in the area that led to the kidnapping of an American soldier.

"Being taken hostage is not an option," says Bernal.

A tiny red flare warns potential intruders not to approach — but it's the figures you can't see who pose the greatest threat to Fiddler’s Green, located at what commanders call a “chokepoint to Taliban activity.”

Yesterday, an IED was found on Route 605, a main supply route not far from the entrance to the base.

But despite the recent spate of American deaths, the Taliban kidnapping of a soldier in the Northeast and the many local opportunities for danger, the 3/ll Marines remain calm.

“I’m confident the Marines have my back,” says Sgt. Scott Whittington, a combat correspondent who routinely ventures outside the wire to capture images of Marines in different war zones. Like many of his fellow Marines, Whittington has combat experience in Iraq and a calm confidence that comes with having been in similar situations.

But Afghanistan is no Iraq.

Bernal is the first line of defense on a barebones base where many Marines are sleeping in hand-dug pits to avoid being wounded by indirect fire. He puts his trust in his unit, and in its mission, which is to secure and hold strategic ground. "I have total faith in our commander," he says.

“One hundred percent accountability is key,” Captain Chad Altheiser, commanding officer of Battery “I,” told FOXNews.com. He has never been to Afghanistan, but he has completed two tours in Iraq. The experience shows.

“We keep security tight here at the camp,” says Altheiser, whose focus on personal safety is only partly explained by the fact that he is expecting a newborn son within days.

Throughout Afghanistan, troops have been killed in action, but that hasn’t been a major concern. News doesn't reach Fiddler's Green 24/7, and because of a lack of Internet and phones, most of the 3/11 Marines are using pen and paper to send letters to loved ones back home.

“No media out here, not sure what’s really going on out there,” Corporal Tyler Ledbetter told FOXNews.com.

Ledbetter, who is three months into a 7-month tour in Afghanistan, refused to comment on the possibility of abduction, but was quick to explain why the rising death toll did not faze him.

“We’re the best trained fighting force in the world,” he said.

Throughout the day, redundant checks are designed to account for Marines. “Accountability. Eyes on every Marine, pre-combat checks, pre-combat inspections,” said battalion commander Lt. Chris Lewis. “Physical and visual accountability, nothing less."

The battle-hardened command is much more stoic than the younger grunts with guns at the gate.

“Personally I have no fear of being kidnapped. Accountability is very strong for the Marines,” said Sgt. Christopher Rye, a 26-year old Marine combat camera photographer.

In the Combat Operations Center, one of the few areas with electricity and some climate control, Battalion Adjutant 1st Lt. Adam McLaurin is brief and blunt. “I’m not focused on casualties,” says the Gainesville, Fla., native, who is on his first deployment.

“We really are just focused on what lies ahead.”

Matt Sanchez is embedded with the 3rd Battalion, 11th Marines in Helmand Province in Afghanistan.