The entire premise of the game: four Elites Are More Glamorous Special Ops soldiers are assigned the task to take down not just the most powerful drug cartel in the world but what is effectively now the government of Bolivia. They kill literally hundreds of cartel sicarios, arm the local La Résistance, and do a lot of covert operations that eventually break the Santa Blacna cartel financially, politically, and militarily. El Sueno may end up being a Karma Houdini but the nation of Bolivia is, at least, free from the Santa Blanca cartels control.
Nomad and Karen Bowman both contribute heavily to this, averting the Good Is Dumb trope by being Genius Bruiser and The Chessmaster both. Nomad, in particular, manages to come up with many of the Batman Gambit plans that severely undermine the cartel's influence in the region like getting blackmail material on politicians and framing individuals for the Ghost's actions. Karen, by contrast, carries the other half of the burden by sorting through all the vast information the Ghosts collect to create their target profiles.
The takedown of El Muro is particularly well done as the Ghosts start an Enemy Civil War between El Sueno and his chief security advisor by assassinating Muro's little brother La Plaga. They also appeal to the better nature of General Baro and convince him to turn UNIDAD against the cartels, dramatically weakening the cartel's ability to function. While El Sueno easily defeats El Muro and the latter refuses to cooperate with America, they still manage to inflict massive damage on Santa Blanca's ability to deal with its enemies.
The takedown of El Yayo and La Gringa also deserves mention as the Ghosts suffer some setbacks like El Emisario killing himself but organize a peasant revolt against Madame Coca and take down their Smug Snake chemist as well as a Genius Bruiser. They then manage to turn both El Yayo and La Gringa against El Sueno, making sure they have ample evidence against the cartel as well as knowledge of its businesses. Notably, at one point the Ghosts demonstrate Good Is Not Soft by blowing up two oil fields to get a chemical company to stop helping Santa Blanca.
Taking down Nidia Flores is one of the hardest of the games because you need to attack her massive trafficking empire smart. You have to destroy submarines as well as experimental boats, you have to convince Santa Blanca's accountant she's stealing from the cartel (as well as help him escape her vengeance), and you have to also shut down a guy running a human trafficking operation alongside his cocaine smuggling. Even then Nidia almost gets away with it and you have to chase down an armored convoy before destroying it.
El Sueno, himself, managed to be a Complete Monster who arguably deserved to win. Starting as a penniless farmer in Mexico, he managed to not only conquer the local cartel after working his way from the bottom but had a Visionary Villain plot to conquer his own country, which he did with Bolivia. He then ran a Pragmatic Villainy campaign that worked with extensive propaganda to make a Villain with Good Publicity beloved by all. Sauron could have learned a few things from El Sueno. He also manages to get away with all of his crimes and becomes a Karma Houdini if you get the Good Ending.
Pac Katari fully intends to take down El Sueno with an army of rebels outfitted by the Ghosts with APCs, helicopters, planes, and military supplies. El Sueno kills Pac Katari personally and shows why he's the most dangerous man in Bolivia. Hell, he even presents Pac's head to you. What Pac thought would be a coup de gras for himself ended up being another for El Sueno.
El Sueno is also implied to have personally killed all of El Muro's UNIDAD assassins as well.
After you take down your first cartel head, El Sueno invites you to a meeting. Naturally, your teammates (as well as Bowman) suspect an ambush. When you show up, you find only four luxury cars and a ringing phone. When you pick up the phone, El Sueno offers you a large amount of money to become his personal hit squad (with the cars as a down payment), praising you as some of the deadliest individuals on the planet. Nomad flatly rejects his offer, and reminds Sueño that the Ghosts are in Bolivia to kill him, before ending the call. Bonus points if you torch all four cars before leaving, just to show Sueño that you aren't screwing around.
El Cerebro's plan to escape using his lead sub designer as a decoy before the Ghosts even arrive in the province is pretty damn impressive. Even the Ghosts are impressed, with at least one of your squad calling it supervillain-level stuff.
The crossover mission with Rainbow Six Siege, "Operation: Archangel" has the Ghosts work alongside Twitch, Valkyrie and Caveira as they seek to rescue Caveira's brother, an officer of the Brazilian Federal Police who's undercover with Santa Blanca. The fact that the two biggest Badass Crews in the Clancyverse get to team up is awesome in its own right.
Twitch and Caveira both compliment the Ghosts on their skills and suggest that Ghost Recon and Rainbow should work together more, possibly hinting at further crossovers in the future.
When Caveira's brother is extracted, he refuses to give Bowman his Intel. When she threatens to ship him off to a black site, the Rainbow operatives make it clear that's not going to happen. Considering this is Bowman they got to back down, that's saying something.
Two words: Future Soldier. Another two; Scott Mitchell. They haven't forgotten about one of the most popular games in the series, and alongside Mitchell and Kozak, active camouflage returns. Not just in use by the other Ghosts, though; a prototype is the event reward, as a backpack. Crouch for a few seconds with it, and viola!
One of the first special operations is plagued with Nightmare Fuel but it's also pretty awesome in its own way: a Ghost Recon team taking on a freaking Yautja and winning.
The slow but steady growth of the Katari 26 rebels. At the start they maybe hold a few outposts and barely have the strength to fight without your help. With each support mission their capabilities expand to the point where they have technicals, helicopters, mortar batteries, snipers, heavy machine gunners, and platoons of men ready to fight to free Bolivia, available for battle whenever the Ghosts need them. Upgrade them enough, and the rebels will tear through Santa Blanca and even UNIDAD's best with ease, wiping out entire outposts by themselves if the Ghosts summon them. Too bad Pac Katari turns them on you at the end. Even if they're apparently crushed by Fallen Ghosts, the fact that the Ghosts can still summon them for help and eventually start rebuilding them suggests that their rebellion is Not Quite Dead despite the death of their leader.
Most enemies brought into safehouses to meet with Bowman are scared, nervous, or try to act tough, then quickly fall apart in the face of Bowman's tough talk. Not La Santera.
Bowman: You know, people like you aren't treated very nicely in prison. Other inmates tend to make their life hell. (La Santera moves forward and looks her dead in the eye) La Santera: I have the faith to survive in hell. (Bowman then shakes her hand, impressed.) Bowman: I look forward to testing that faith. Because you've never seen my hell. (La Santera rips her hand out of Bowman's grip and continues glaring until Nomad leads her away.)
If you are sufficiently daring enough, you can get into massive, in-game-day-long battles with UNIDAD, summoning rebels to try and even the odds against dozens of soldiers. While there's a tremendous likelihood that they'll overpower you with force and resources and kill you, UNIDAD will eventually call off the fight at some point, usually when they suddenly stop sending vehicles, letting you withdraw from the area and making them call off the attack. Congratulations - you fended off the best army in the game and won. Bowman was not kidding when she said the Ghosts had the strength to take down an army.
