GERDA SERAI, Afghanistan — Ever since 1st Squadron, 40th Cavalry Regiment built Patrol Base Devoe in April, life has been a little bit better around the area that Troop C controls. The base’s position on a mountaintop allows the troops to control an area that was once the launch site for frequent rocket and mortar attacks on nearby Combat Outpost Wilderness.

But what seems on the surface to be an unambiguous good has actually created a new challenge for the unit. The insurgents’ abandonment of long-familiar patterns has Troop C busy working to uncover the enemy fighters’ new methods.

The challenge illustrates how fluid and complex counterinsurgency warfare is in the most contested parts of Afghanistan, although the dynamics are actually a familiar paradox of counterinsurgency warfare known to planners and system theorists as a “wicked problem.”

These are problems without a single solution or an indicator of when they’re solved. Most significantly, simply trying to solve the problem changes it so that the solution can’t be duplicated. The most successful solutions, in fact, can lose effectiveness fastest because they put more pressure on insurgents to adjust their approach.

Previous units, for example, used to have a good idea which routes and safe havens enemy fighters used to move about the area. That traffic is still out there, but the new patrol base forced the insurgents to change their routes and find new safe havens, said Capt. Neal Erickson, the Troop C commander.

First Lt. Eugene Miranda, the leader of a platoon attached to Troop C, said insurgents intimidate village elders and use the towns as a shield. Most villages have at least one Taliban spy. Locals are so sensitive to Taliban presence that Miranda calls the enemy fighters “black sheep” as a way to help the locals feel more comfortable discussing insurgent activity.

But a comprehensive approach can help curb these influences where any one tactic alone might fail. Tribes are the center of relationship networks in Troop C’s area, in contrast to other parts of Paktia province where individual villages are key. So the unit has been singling out “areas of tribal influence” to beef up presence, improve security and increase the Afghan government’s influence — primarily through the Afghan army and police.

Monday marked the start of a three-day patrol in the Toro Kheyl tribal area. The soldiers spent part of the time having tea with local leaders, part of the time patrolling and part of the time searching for weapons caches. Along the way, they visited multiple villages and passed many outlying homes.

“Not many people get the chance to come to Afghanistan and climb to the top of a mountain looking for weapons and insurgents,” said Pfc. Justin Moore.

The soldiers collect information and build relationships in the tribal areas, so military leaders can put the pieces together to form a clear picture.

“I’m not looking at individual villages. I’m looking at tribes,” Erickson said.

Terrain and development can make it hard for enemy fighters to change their tactics completely. The Americans are well aware that the Gerda Serai District bazaar is a popular site for recruiting insurgents and staging roadside attacks, said Sgt. 1st Class Andrew Spath, a platoon sergeant in a platoon attached to Troop C. The heavy traffic through the market makes it easy for enemy fighters to communicate without raising too many eyebrows. Insurgents often ferret away their weapons in the hills within an easy walk of the shops.

Minutes after Spath made those comments, a patrol through the Khar Kheyl area just outside the market uncovered seven cache sites filled with homemade explosives, roadside bomb materials, Afghan army clothing and assorted weaponry.

“It totally messes with their world,” Erickson said.