Editor's note: GlobalPost's correspondent John Otis had a rare opportunity to embed with the Colombian army during a mission against the FARC. This two-part series details his time in the battle zone and the rise in rebel deserters.

LA MACARENA, Colombia — Accompanying frontline Colombian soldiers is not something I would have tried when I first arrived here 12 years ago. At the time, the army was getting chewed up by Marxist rebels who overran military bases and kidnapped hundreds of troops. Back then, it would have been safer to embed with the guerrillas.

But thanks to improved intelligence, joint operations involving the army, air force and marines, and billions in aid from the United States, the Colombian military has scored some impressive victories. The Revolutionary Armed Forces of Colombia, the nation’s largest rebel army known as the FARC, have been reduced from 18,000 to about 9,000 fighters.

Despite the good news, the Colombian army can be gun shy around reporters. It took me more than a year of lobbying to arrange for a three-day embed that included just three hours in the actual battle zone. Yet that was enough time see why winning the war remains an elusive goal for the Colombian army.

Day 1

8 a.m.: A military plane deposits me in the southern town of La Macarena, home to the FUDRA, the Colombian army’s rapid reaction force. Over coffee, FUDRA commander Gen. Miguel Perez shows me a homemade rebel land mine built from plastic PVC tubing. His troops are spending so much time in the jungle against a weakened FARC that most army casualties are now the result of land mines or tropical illnesses, like malaria and the flesh-eating disease leishmaniasis.

10 a.m.: Perez sends me down the road a few miles to the FUDRA training camp. I recognize the spot, which used to be a FARC bivouac. I spent a long afternoon here in 2001 interviewing guerrillas as they slaughtered a cow to prepare lunch. Soldiers now use the bunkhouses, kitchens and clothes-washing facilities built by the enemy. “We kicked them out of a place where the rebels felt like kings,” said Pvt. Jose Villalba, an eight-year army veteran. “That’s why we feel we’re winning the war. The FARC thought they were untouchable.”

Noon: Villalba is a member of Puma Company, a group of elite commandos who at the start of tomorrow’s raid will leap out of helicopters and rappel down ropes. Perez orders me to learn how to rappel in case there’s no room on the ground to land a chopper. After climbing up a 75-foot-tall tree, the commandos practice by falling backward off a wooden platform and sliding down a rope. I’m scared but before I can wuss out, I’m clipped into a harness and handed a Kevlar helmet and a pair of leather gloves. With one hand forward and one behind my back, I grip the cord as if it were a tow rope on a ski hill. After taking the plunge, my gloved hands serve as brakes as I slide down the rope. I land safely on a stack of sand bags but lose style points for splaying my legs. Press them together, I’m told, or when it's time to do this for real I might get snagged on tree branches.

8 p.m.: In the FUDRA war room, Perez explains the joint military operation to two dozen officers. The target is a FARC camp occupied by bodyguards of a rebel commander known as Mono Jojoy, who heads the FARC’s Eastern Bloc. A guerrilla deserter provided the camp location and the Colombian Air Force confirmed the information. In a pre-dawn blitz, Super Tucano aircraft will pound the area with bombs, Perez says. Then Puma Company troops wearing night-vision goggles will be airlifted to the spot to pursue any rebel survivors. All the while, Black Hawk helicopters and an AC-47 gunship will circle overhead providing cover. H-Hour is 5:40 a.m.

DAY 2

7 a.m.: Perez decides that I’ll ride along with him in a chopper to observe the initial stage of the assault from a safe distance. But low-lying clouds delay the operation. As we climb aboard the general’s Huey, the sun is rising. Under cover of the night, Perez says, “we would have had a huge advantage. But now the guerrillas are awake. They’ve had breakfast. And they’ve got their guns in their hands.”

8 a.m.: We fly toward the battlefield located just west of the butte-shaped Macarena Mountains. The area is a historic FARC stronghold and the rugged ridges, caves and rain forest offer plenty of hiding places. I feel like a spectator at an extreme, to-the-death sporting event. Yet from the air, war seems distant and sterile. The bombs from the Super Tucanos have blasted over trees and opened huge orange craters. We watch as helicopters hover just above the jungle canopy. One-by-one the commandos slide down ropes and disappear into the green expanse.

9 a.m.: Instead of landing, our chopper turns around and heads home. What’s going on?

Noon: Back at the FUDRA base, Perez appears to be having second thoughts about this whole embedding business. He is vague about what’s happening on the ground, saying only that conditions are not secure enough to insert a reporter into the hot zone. We’ll try again tomorrow.

DAY 3:

8 a.m.: I board a Black Hawk helicopter along with soldiers who carry aboard backpacks and gunny sacks bulging with food and camping gear. For part of the trip, we fly just above the treetops, a maneuver that gives rebel sharpshooters little time to take aim. We touch down in a clearing by the bend in a river. The troops jump out and more soldiers pile aboard along with an explosives-sniffing dog that was bitten on one of its paws by a snake. As we lift into the air, the dog whines and licks his wound.

8:30 a.m.: The chopper touches down on a dirt road and I catch up with Puma Company. Wearing green, brown and black face paint and with leaves protruding from their helmet netting, the commandos are almost invisible in the forest. We use our hands to push past trees and bushes because hacking at the underbrush with machetes would leave an obvious trail. I stumble on the vines trying to keep up. My hands, which are my only exposed flesh, are set upon by ants whose bite feels like a hornet sting.

8:35 a.m.: Lowering his voice to a whisper, Capt. Frank Olaya, the 30-year-old commander of Puma Company, shows me the mission's war trophy: a couple of rough beds made of boards and leaves. It seems that while the guerrillas were once here, they cleared out many months ago. Over the past 24 hours, Olaya’s men haven’t come across a single FARC rebel. The young officer calls it proof that the army is gaining control of the countryside. But there’s no disguising the fact that in a meticulously planned operation the military mobilized 11 aircraft, dropped nine bombs and inserted three dozen troops into a patch of jungle with no guerrillas.

9:30 a.m.: Finally, the troops find someone to scrutinize. Olaya pulls over a farmer driving a pickup down the rutted gravel road. The man seems a bit twitchy. Maybe he’s a FARC militiaman in civilian clothes. Or maybe he’s just intimidated by so many soldiers. Either way, he refuses to speak to an army camera crew because he fears the FARC might see the footage and retaliate. The soldiers, he points out, may be providing some temporary security but they will soon be pulling out. He has to live here.

Noon: Back at FUDRA headquarters, Perez is in a foul mood. I wonder if he’ll catch hell for launching an unnecessary mission that, according to one Defense Ministry analyst, probably cost more than half a million dollars. Later, I comment on the difficulty of tracking down every last guerrilla in the thick jungle. Perez counters that the real goal is to score enough military victories that the rebels lose their will to fight. One sign of success, he says, is the rising number of FARC deserters, who often provide key intelligence. But not all their facts check out. Indeed, Puma Company’s failed assault was based on faulty information from a FARC informant.

4 p.m.: Olaya and the other soldiers of Puma Company regroup at their training camp. Though they were shut out on this particular mission, they’ll have many more cracks at the FARC. And they’re pleased that all of the 36 soldiers who rappelled into the jungle have made it back alive.

Read the second part of this series, about FARC deserters.