KABUL, Afghanistan -- As the beating heart of Afghanistan, the city of Kabul relies on several checkpoints to screen vehicles and people traveling along its major arteries.

Many of those roads lead to the most crucial part of the capital city -- the Green Zone. A heavily fortified area, it is where the country's key government buildings and several foreign embassies and military offices are headquartered.

"This is the nerve center of the country," said Capt. Jay Beeman, a team leader with 1st Security Force Assistance Brigade. "The security around the Green Zone is absolutely important, because anything that destabilizes the seat of government obviously destabilizes the country."

After a string of high-profile attacks, including a truck bomb that killed more than 150 near the German embassy in May 2017, the Kabul Enhanced Security Zone was created to serve as a buffer around the Green Zone.

The zone has tightened security by adding more checkpoints, improving intelligence sharing and delineating responsibilities among Afghan security entities.

Behind many of those efforts are 1st SFAB advisors, such as those on Beeman's combat advisor team.

Part of the brigade's 5th Battalion, the captain's team oversees progress in Afghan National Police Unit 01, which was formed following last year's deadly bombing.

The team trains and offers advice to the unit's leaders and police officers manning almost 30 checkpoints that protect the city's most sensitive structures.

"It's super complex what they're dealing with out there [in] a city of 5 million people," he said. "Their capacity to do what they're asked to do is actually quite high."

TWO LAYERS OF DEFENSE

On the fringes of the city, there are also eight city gates where Afghan National Army soldiers serve as the first line of defense.

On any given day, over 100,000 vehicles pass in and out of the gates, said Lt. Col. Zachary Miller, commander of the 1st SFAB's 5th Battalion.

One such gate handles traffic on Highway 1, which travels northeast from Ghanzi, Kandahar and other western portions of the country.

"This is the ring road, the most important road in all of Afghanistan," Miller said during a brief visit to the gate. "Even if you're bypassing Kabul, you still have to transit through this road and it still goes basically through the middle of the city."

As part of its advising efforts, Miller's battalion aims to boost security measures at the gates by guiding contracts worth millions of dollars through a lengthy bureaucratic process.

Those contracts include explosive detection dogs, electricity to power lights and equipment, and new scanners that will be able to check more cars and trucks as they pass through.

While bombs remain the gravest concern, Afghan soldiers have also been trained to search for other illegal activities.

"It's not just about explosives, it's also about illegal weapons that come up this way, materials that can be used to make bombs and even things like human trafficking," Miller said.

During a recent search at a different city gate, suspected human traffickers were arrested on their way out of the east side of the city along Jalalabad Highway, which eventually leads into Pakistan.

Insurgents have been known to kidnap and sexually abuse children from Kabul or even use them as suicide bombers.

"These are young children who are susceptible to all kinds of deceptive practices," Miller said. "There's a high probability that they were either going to an [Islamic State group] area or all the way into Pakistan.

"Great job by the [Afghan] army unit that was there to catch that."

Throughout the 1st SFAB's deployment, which ends this month, Miller said he has seen significant improvements by the Afghan soldiers and police officers.

"We've seen a pretty good increase in the rate of operations, how quickly they are doing them as well as the quality they are doing them," he said.

Progress continues to be made in their tactical skills, but also in the other things that help an organization run, such as logistics, movement of people, pay issues and training.

Advisors also help them make connections within their own organization and with the coalition to solve problems.

"There are a lot of different kinds of advising that goes on here," Miller said. "Some of it might seem kind of mundane, but it is extremely important and that's sitting down in the workplaces of your Afghan counterparts and working through the regular stuff that we have to deal with in our own military."

AFGHAN-LED SECURITY

Working as an advisor has been a major shift for Beeman, whose last job was an engineer company commander in the 101st Airborne Division (Air Assault).

Now in charge of five highly-skilled advisors, instead of over 100 Soldiers, he and his team have more autonomy than they would in a traditional unit.

The captain, though, still uses several lessons he has learned over his career.

Whether it be learning dynamic environments, how to implement different resources, or supporting elements within an organization, he said they all transition to his current role.

"It's the same when you start looking at how to make something better, how to inject a different capability into a problem set," he said. "I think it transitioned pretty well."

His team of advisors will often pop in at the Afghan police checkpoints to observe officers and provide tips, if needed.

On a recent mission, Beeman went over how to search vehicles with an explosive detection dog as officers stopped vehicles along a city road.

Afghan 1st Sgt. Mehrab, who was in charge of the checkpoint, said he was grateful for the team's assistance.

"We have a good relationship with them," he said through an interpreter. "We always thank them for their support."

He is always open to suggestions, he said, that help him and his officers protect their nation.

"This is the only aim that I have," he said. "I should serve my country and also my people."

That sort of patriotic attitude is what the advisors like to see. And when the Afghans take the lead, guarding the checkpoints and city gates, it resonates throughout the entire population.

"They are the face of the country," Beeman said. "For the everyday civilian population to see they have security from their own government, their own police force, their own army, is critical to having faith in the development of the country."