The Psychopath: Then there's the second kind, the Psycho for Hire who just joined up for the plunder, rape and massacring of civilians and doesn't care whose banner they're doing it under. If he wasn't in the army he'd be a Serial Killer or mass murderer. The slightly less psychopathic and/or stupid ones will skew more towards Blood Knight; civilians still aren't quite out of the water, but they're way more into the combat part of the equation and generally avoid going after civilians because they don't fight back and thus aren't exciting. He's also the most likely to get himself killed; jingos usually have like-minded comrades who will help save their asses, unwilling conscripts are solely motivated by their own survival, and broken soldiers still take pains to stay alive so that they can keep helping their comrades along. Blood-crazed maniacs, on the other hand, tend to do unbelievably idiotic things that get them offed fairly quickly, and if they don't get taken out by the enemy, there's also a fairly strong likelihood that their own comrades will off them out of disgust or (more likely) because they're a liability.
The Unwilling Conscript: The third kind is your regular neighborhood boy who has been conscripted into the army, has absolutely no interest in war, hates it all and has only his own personal survival at stake. He's nothing but Cannon Fodder and he knows it — with nothing to gain from the fighting, the knowledge that he is expendable tips him over the edge into madness. This kind hates everybody, including his own officers, though it's the enemy civillians who will likely bear the brunt of his wrath. Expect lots of Rape, Pillage, and Burn; Fragging incidents may occur. They still exist in armies not based on conscription in a modified form, usually as a kid who technically entered voluntarily but is essentially there because it was his only viable option; expect to see the same bitter, desperate viciousness and general disregard for the lives of others. Also the most likely to defect or desert if he gets pissed off enough.
The Broken Soldier: Finally there's the fourth kind; he was a Nice Guy at one time, just trying to take care of his buddies and protect his home - but then he saw or experienced something that broke him inside, and now he just wants to get things done as efficiently as possible. This would be the Shell-Shocked Veteran, and he's a lot more dangerous than the other three - he's neither stupid, crazy, nor angry, just'pragmatic'. I Did What I Had to Do is practically his mantra; if the easiest solution that has the smallest potential body count on his side is also unbelievably brutal and cruel, he'll employ it nonetheless and worry about the horror of what he did after the fact. He's fully aware that what he's doing is horrible and unforgivable, and if it doesn't haunt him and keep him up at night, he's most likely dead to the world and would probably be blowing his head off if he didn't have comrades to see through the war.
During the Ishval flashbacks we see that many of the Amestrian soldiers, including Roy Mustang, Riza Hawkeye, Maes Hughes, Basque Grand and even Major Armstrong acted like this during the genocide, running the full range of Types 1, 2, 3, and 4. Unlike Kimblee, they're all haunted by their actions, and deeply regret them. In the first anime, Barry the Chopper argues that people really do want to kill each other, but won't do it without permission from the government; hence why people join the army in the first place. Manga!Kimblee makes a similar speech, in which he questions the motivations of Roy and his friends, suggesting that if they were only willing to kill a few people, but not thousands, they shouldn't have joined the army in the first place.
"Look your victims in the eye. And never, forget them. They certainly won't forget you."
There's also Retired Badass Giolio Comanche, who seems to have enjoyed his time at the front a little too much going off the Slasher Smile he displays when Order #3066 is issued.
Along similar lines to Kimblee, Sir Luciano Bradley of Code Geass is a Psycho for Hire type who actually comments that he loves the military as it allows him to kill lots of people and get rewarded for doing so.
And at least a good chunk of the Britannian troops. If a few simple words from your superior is enough to get you to gun down unarmed civilians without a sweat, there might be something wrong with you.
Yazan recieved an expy in ZZ Gundam's Rakan Dahkaran, a ruthless Axis-Zeon Ace Pilot who ignores the rules of war and aims to kill as many of the enemy as possible, regardless of whether they are actually combatants. One iconic scene has him impassively firing on hospital ships and refugee craft as they attempt to flee from a Colony Drop; he wants to make sure that no one escapes the blast radius.
Decil Galette of Gundam AGE takes the worst qualities of both Yazan and Ali and combines them into a single, nasty childsized package, treating war as a game and his victims as toys. The timeskip has not improved him, and the disconcerting enthusiasm he shows whenever's he's turned loose on his enemies is if anything more disturbing on a thirty-three year old.
Two of Noin's former trainees in an episode of Gundam Wing go this route, sadistically murdering their opponents and laughing over the wreckage. If they weren't members of the army, the'd be Psychos For Hire.
Kagerou-Nostalgia: The vast majority of the soldiers in GeneralKiyotakaKuroda's employ fit into this category. Given that they're sent into battle alongside demons, with orders to butcher and kidnap as many civillians as possible, this is more or less a part of the job description.
Several Naruto villains, although given the nature of the setting comparing them to regular soldiers is iffy. Pre-Heel-Face Turn Gaara is a solid example though, as are all 7 Swordsmen of the Mist.
Black Lagoon: In his backstory, the leader of the Special Forces unit Grey Fox killed a gang of these (led by a Colonel Kilgore type) to protect Vietnamese civilians.
Roberta professes that she was the Jingo while she served in the FARC, killing without remorse to protect the ideals of the Revolution.
The Comedian then immediately calls out Dr. Manhattan for not doing anything to stop him despite being all-powerful. From his perspective, Dr. Manhattan is a sociopathic soldier. This has spawned MANY fanfics where Dr. Manhattan teleported the baby to X.
Deconstructed in the Two-Fisted Tales short story "Kill!", set in the Korean War. On the American side we have have Abner, who continuously sharpens his knife and can't wait to gut some Chinese, while in the Chinese camp we meet Li, who obsessively polishes his submachine gun and compares it to a beautiful woman. In the end, they meet in the field, mortally wound each other and both die unceremoniously.
In Sin City, Marv briefly mentions fighting in a war. It's possible that this could be one of the reasons for his mental state.
Also oddly averted with Wallace. Given Sin City's penchant for violent heroes, Wallace is a former Navy SEAL, yet is one of the nicest characters in the series.
Captain Atom and Green Lantern villain Major Force was already serving a life sentence in a military prison, before being used as a test subject for a Super Soldier experiment. The end result? Turning a remorseless psychotic murderer into a Person of Mass Destruction.
Nuke from Daredevil: Born Again is a product of an attempt at making another Captain America. He's a Super Soldier with heightened reflexes, drug-fuelled rage, and hardened plastic under his skin. He's also totally off his rocker, thinks he's still fighting The Vietnam War, and will slaughter anyone he thinks is threatening "our boys"; his gun keeps a count of his kills.
In Route 666, Berkely went to war just to sate his bloodthirst - when the war ended, he became a serial killer instead. He wanted to team up with Cassie just so he could kill with a fairly clean conscience again.
Suicida, leader of the Gang Green in Marshal Law. Like most "superheroes" in the setting, including Law himself, he and his fellow gang members are disaffected veterans of the catastrophic South American war known as "the Zone". He was trained to kill in the most brutal fashion imaginable, and resents the idea that his violent nature can somehow be turned on and off like a faucet. He wears a necklace of human ears and just wants to hurt everything he sees. Law doesn't like Suicida, but doesn't blame him for his feelings or his behavior, since very few Zone veterans are doing much better.
The Punisher is usually interpreted as this to the point where he cannot even smile at the deeds he does (mentioned when he kills Bushwhacker.) He has essentially taken his war to the streets showing no pity, remorse or fear against gangsters, psychos, killers, rapists, criminals or Hired Guns. Some suggest it was his experience in Vietnam that made him this way, making a Deal with the Devil, all works show it was losing his family that made him nuts. Whatever the case he is a broken type 1 and 4, to the point where he regrets not having someone to kill, or even having a wife and kids in the first place (though this can be interpreted as if he didn't they wouldn't have been in the park, they wouldn't have been killed and they he wouldn't have turned into the sociopath he is today.)
Sergeant Shining Armor from Shell Shock is a terrifying example of one of these. He doesn't care. He doesn't relent. He doesn't apologize. He just wants blood. He doesn't care who bleeds.
Captain Edward Grey was broken by his experience in Akuze. Put through a Treadstone-style programme to be brought back to combat readiness, while he still wants to do the right thing, he's quick to opt for the callous, vicious Kill 'em All option against slavers, xenophobic lynch mobs and other criminal scum.
This is the justification given in chapter 38 for why Blacklight black ops troops are so easy to defeat, at least for elite superhuman warriors like Adam, Hannibal and Johann - The Alliance Intelligence Agency selects for the jingoistic ultranationalists willing to cross any line to protect their interests, and as it turns out being a talented combatant and being one willing to get his hands dirty are categories that rarely overlap.
Maggot from The Dirty Dozen is perhaps one of the better pre-Vietnam examples in film. He's a fundamentalist, misogynistic rapist and killer of women who turns on his own team when he can't control his urges during the mission.
The above scene is from Michael Herr's book Dispatches which describes his experiences as a war correspondent in Vietnam. Herr was a co-screenwriter for Full Metal Jacket and was nominated for an Academy Award for his work.
Almost the entire Japanese Army in City of Life and Death. It's a movie about the Rape of Nanking, so that goes without saying.
In Tim Burton's Sleepy Hollow, the Headless Horseman was one of these in life. While the other Hessians were mercenaries, he went to fight in America for the love of killing, and loss of life, head, and will hasn't abated that love.
The soldiers in 28 Days Later. Besides the Only Sane Man, the CO wants nubile women to try and keep the rest of his soldiers under control. Think about that for a minute.
The main characters of Inglourious Basterds are a group of American Saboteurs who enter Nazi-Occupied France to unleash hell upon Nazis from the inside, and employ terror tactics. Notable however is Hugo Stiglitz, a German-born Ax-CrazyStoic who the Basterds recruited due to his reputation of killing 13 officers in their sleep (or waking them up just before he kills them).
Sergeant Tony Meserve in Casualties of War. He kidnaps, rapes, and kills a young village girl, then tries to kill PFC Eriksson with a grenade in the latrine.
Paul Lazzaro in Slaughterhouse-Five. This is clearly defined when he recounts the story of killing a dog by putting some clock parts into a steak that he gives to the dog that bit him. Any time someone makes him angry, he threatens that person with violence, then in the end of the movie, he kills Billy Pilgrim, just as he said he would.
However, it is averted by the Union soldiers Tuco and Blondie encounter later on, who are led by a likable, humorous fellow who happens to be A Father to His Men, making his sudden death during the ensuing battle a surprisingly tear-jerking moment for a bit character, and there's also a younger lieutenant who seems to be an ordinary man caught up in a war he does not understand.
Leone revisits the trope in Duck, You Sucker! (aka A Fistful of Dynamite) in the form of the Mexican soldiers serving under Colonel Gunther Reza. The Mexican army as conceived by Leone seems intent on imprisoning or killing every single person they meet, and their look is modelled on that of the fascist stormtroopers and German soldiers that Leone saw in Italy when he was a child. Reza himself is a terrifying Type II and Implacable Man to boot, despite never saying a word.
Ewan McStarley, Vinnie Jones' character in The Condemned— an SAS operative who became a Condemned Contestant after setting fire to a Rwandan village, executing 17 men, raping 9 women, and torturing various others.
In the Doom movie, Sarge shows himself to be this, at one point killing the rookie member of his team for refusing his order to kill a room full of unarmed civilians. Small wonder, then, that he mutates into the protagonist's final adversary after becoming infected.
Lawrence of Arabia grows closer and closer to this trope as the movie goes on, finally culminating in the massacre at Tafas.
In Hollow Man 2, the direct-to-video sequel of Hollow Man, the antagonist Michael Griffin was one of these even before being injected with the invisibilty serum. His commanding officer kept him from being charged for war crimes committed in Iraq so he could be part of the project. Since the real purpose of the project was to create a perfect assassin to kill off the project head's political enemies, a test subject with little to no morality was just what the project needed. When Griffin becomes even crazier due to the lethal side effects of the serum which only a special chemical booster can alleviate, his former commanding officer learns the hard way that giving a murderous sociopath invisibility powers and a reason to hate you can backfire.
In the movie version of Jack Reacher, the gunman, an ex-soldier, who guns down several people in a Parking Garage is described as being a sociopath who went out of his way to kill civilians in Afghanistan.
Jack Reacher: There's four kinds of people who join the military. There's the people for whom its a family tradition. There's the people who do it out of patriotism. There's the people who simply want a job. And then there's the last kind; the kind who enlist because its a legal opportunity to take a human life.
Andrew Scott from Universal Soldier. he was a Sergeant in The Vietnam War, where he goes renegade as he starts butchering civilians and kills his own squad when they try to stop him. He cuts off the ears of his victims and wears them in a necklace. He orders Private Luc Deveraux to kill the two remaining 'traitors', two Vietnamese children, doing the job himself when Deveraux refuses. Both are reborn years later as memory-wiped Super Soldiers. As soon as Scott regains his memories he kills his controllers and goes on a blood-filled vendetta across the States to punish Deveraux for disobeying his illegal orders back in Vietnam, graphically killing anyone who gets in his way. At the end he takes Deveraux's elderly parents and his love interest hostage, awarding all of them the death penalty. Despite claims earlier in the film that he thinks he's still fighting the insurgents in Vietnam, Scott later plainly admits that he's fully aware where he is and what he's doing, and his only motive is revenge for Deveraux refusing to partake in his atrocities.
Conspiracy: Deconstructed. SS Major Rudolf Lange is the closest you could get to this, as he's leading one of a number of huge death squads through the occupied Soviet Union shooting unarmed civilians en masse and encouraging racist locals to kill Jews in mobs. However, he and his men are becoming increasingly disturbed by the sheer level of inhumanity they're supposed to inhabit. Heydrich introduces the gas chambers to make the murders easier to carry out for the perpetrators.
Mentioned in Discworld's Night Watch, where Sergeant Carcer is described as "the sort that joins up for the plundering...the kind you have to end up hanging as an example to the men".
In A Song of Ice and Fire, most knights and men-at-arms conform to this trope, particularly those assigned to pillage peasant villages for information and supplies. One character gives a sympathetic monologue that any man conscripted into war can become this way if he survives long enough.
Justified in that the series takes place in a medieval period. There are no conscripts or discipline; the only difference between a French or British invasion from a Viking raid was the scale and technology. In fact, a Viking raid would often be cleaner, as they would be operating on their own schedules and thus be better fed and less desperate than any soldier. Ahem--sorry.
Gregor Clegane is a solid example of Type 2. He only fights under Tywin for a chance to hurt people, and when he's not soldiering he's murdering and raping people for his own amusement.
Andrea from The Zone series of World War III novels by James Rouch. A stunningly beautiful East German woman with a Mysterious Past and a passionate hatred of communists. She bonds with various soldiers (though never sexually) long enough to absorb their specialist skills, then callously severs the connection to move on to the next teacher. Warning: Keep away from prisoners.
Hakeswill in Sharpe. Senior officers love him (except the ones with real integrity), everyone who knows what he's really like loathes him.
Brigadier Guy Loup is an example from the French side. When the Riflemen capture two of his men responsible for a particularly brutal massacre of a Spanish village, Sharpe has them executed on the spot. He has no shortage of volunteers for the firing squad.
Corporal Lehto in Väinö Linna's The Unknown Soldier. He is a complete sociopath, bully and ruthless to both enemy and his own squad. His end is tragic: he walks into an ambush in night fight, gets shot and wounded on his spine, gets paralyzed and shoots himself because he considers himself now as cripple and bottom of the pecking order. He doesn't give himself any more mercy or respect than to anyone else, and sees suicide as the only logical conclusion.
In Harry Turtledove's The Great War trilogy, one of the PoV characters is Gordon McSweeny, a charming Corporal who, being staunchly Protestant, believes himself to the instrument of God's wrath upon the Confederates, and turned down a command post multiple times. This is because he enjoys personally killing them. With his FLAMETHROWER. He's only slightly nicer to the men under his command; one time not mourning one's death, because he was Greek Orthodox and therefore a heretic, even if he was a nice guy.
Lieutenant Boris Lavochkin, in Settling Accounts is even nuttier, burning and slaughtering his way across the Confederacy. You don't feel particularly bad for his victims (they are after all A Nazi by Any Other Name), but he's still very much this trope, as his sergeant, Chester Martin repeatedly lampshades. On the other side, there are the Freedom Party Guards who to say the least, aren't very nice. What do you expect from SS expies?
This is how most of the civilians view soldiers, even regulars but especially the more common mercenaries, at the start of 1632. Fairly often they're right even and when they're wrong the armies still have to "scavenge" like crazy to keep from starving.
In Tom Clancy's Red Storm Rising, KGB soldiers tend to be portrayed this way, as specifically distinguished from Red Army troops. This is apparent in a scene during the Iceland occupation where Lt. Edwards comes upon a farmhouse whose occupants have been raped and murdered by KGB troops. He rescues the sole surviving daughter in Big Damn Heroes fashion and then proceeds to mete out summary justice to the rapists.
Many examples in the Malazan Book of the Fallen, but the crowning one would have to be Anaster, the First Child of the Dead Seed. He's an Empty Shell of a Death Seeker who commits atrocities in the hopes of forcing someone to kill him, and leads an army of cannibals on a rampage accross the continent, butchering everything in his path seemingly for the sake of it.
Dale in The Thin Red Line is a pre-Vietnam example - a rather slow-witted yet ambitious soldier who seems to take pleasure in doing horrible things to the enemy.
Redmond Barry a.k.a. Barry Lyndon became one of these while fighting in the Seven Year's War. It's implied that Barry's hellish treatment in the Prussian army contributed to him being this way and enthusiastically joining in "foraging" (read Rape, Pillage, and Burn). There's a kind of disturbing scene where in a surprisingly gentle tone he describes a foppish and inexperienced opponent whose skull he bashed in with his musket and whose corpse he looted.
Sergeant Bothari of the Vorkosigan Saga is a more complex version of this. He is a sadistic sociopath, but has enough conscience to realise that random killing is wrong. So he uses military regulations to tell him when it is OK to kill. His commanding officers learn to think very carefully before taking off his leash.
Most of the soldier boys in The Drowned Cities. They talk like Type Is, act like Type IIIs, and are all afflicted with shell shock in one way or another. Sergeant Ocho is a deeply screwed up and angry Type IV, hiding his PTSD behind a wall of bitterness. His commanding officer, Lieutenant Sayle is an icy Type II with a penchant for Cold-Blooded Torture. One of Ocho's men, Soa, is also a Type II, of the Axe CrazyMood-Swinger variety. He has pretensions of being a Type I, but doesn't even really understand what the words mean.
In the backstory of Richard K. Morgan's Thirteen, several nations attempted to genetically and socially engineer Sociopathic Supersoldiers. The projects collectively Went Horribly Right, creating the protagonist (initially Type III shading into IV) and several of the antagonists (Types II and III).
In the Takeshi Kovacs Series, also written by Morgannote and close enough to Thirteen that many speculate they take place later in the same universe, the UN Protectorate's Envoys recruit borderline psychopaths with just the right mix of inhibition and sense of duty. Most end up resorting to crime after they muster out, the titular character usually works as a detective, bodyguard, or mercenary. According to Kovacs they prefer to recruit from more conventional militaries as they cultivate that mindset. Though it's not entirely clear where along the scale he falls given how often he mentions his pre-recruitment adolescence as a gangbanger.
In The Short-Timers, a Vietnam War era novel by Gustav Hasford, Animal Mother is THE sociopathic Marine, although by the end almost all members of the Lusthog Squad display signs of this - to a lesser degree. In The Film of the Book, Full Metal Jacket, this is somewhat overshadowed by the character of the "door-gunner" who sets altogether new levels of sociopathy.
Clone: In this BBC series, Colonel Black (Mark Gatiss) is a solid Type Two, there to enjoy all the torture and murder. Given the tone of the show, he gets a great deal of enjoyment.
Doctor Who: The Sontarans are an entire race of Super Soldiers who behave this way towards their enemies. The one exception is the Combat Medic that the Doctor encounters in "A Good Man Goes To War" who demonstrates that their sociopathy is learned, rather than ingrained. Most Daleks fall under this trope as well, committing genocide at the drop of a hat.
Generation Kill: Lance Corporal Harold Trombley is explicitly stated to be type II as the quote at the top of the page indicates.
JAG: Roscoe Martin, the paraplegic Vietnam veteran in "King of the Fleas" and "The Martin Baker Fan Club", is the broken soldier type who while getting himself in trouble manages to manipulate people around him (including Harm).
LOST: Soldier turned mercenary Martin Keamy appears to have always been sadistic and borderline psycho, but the Island really brings out his sociopathy, resulting in him murdering people left and right for spurious reasons and endangering the lives of his ship's entire crew.
Person of Interest: Detective Carter's backstory has her serving as an Army interrogator in Iraq. She managed to talk a detainee into giving up the location of an insurgent supply cache in exchange for protecting him and his family from said insurgents. Then the soldiers Carter was working with killed him offscreen after he led them to the cache.
He's also got a Complexity Addiction - he uses a missile to try and kill one person. Think about that for a minute.
Lieutenant Trotter is also an example. Disciple of General Ripper Slade Wilson, she willingly engages in kidnapping, brainwashing, and human experimentation in the supposed interests of protecting the US from metahumans. A Knight Templar whom even Flag believes needs stopping.
Her devotion to both Slade and her belief that metahumans need to be stopped gets to a point where she arrests and interrogates three completely normal people, including subtly implying that if they don't answer her questions, they'll never be seen or heard from again. Keep in mind that the only evidence she has against these three is being on Oliver Queen's payroll (Emil), writing a lot of stories about a superhero (Lois), and being Oliver's ex-girlfriend and current business partner (Tess). She badgers them about where the vigilantes are, despite the fact that she has no good reason to think any of them know anything. While she is never flat-out violent towards those three in particular during the interrogations, her orders to move Tess and Emil to a "secure location" heavily sounds like they were either going to be executed or moved to a location where she could use less conversational techniques.
Star Trek: Deep Space Nine: Reese from the episode "The Siege of AR-558" is this. He is shown to be wearing a necklace of ketracel-white tubes (a type drug the enemy needs to survive) picked from killed Jem'Hadar and often sharpening a knife also taken from a dead enemy. He is also used to show the cruelty of war in that he survives while Nice Guy Kellin dies.
Star Trek: Voyager: Maquis crewman Lon Suder kills another crewmember just for looking at him the wrong way. He is Betazoid but tellingly has no empathic or telepathic abilities like others of his race.
One of the numerous dysfunctional soldiers mentioned in Tom Lehrer's song "It makes a fella proud to be a soldier" is Bill. He stabbed a cop in seventh grade, and joined the Army because they'd give him better weapons than he could get on the street. He's described as "real RA material". Although, given his platoon is lead by a Georgian ex-con, he probably is.
The End of the Thirty Years War by Jacek Kaczmarski epitomizes this trope in extremely graphic way.
Hüsker Dü's "You're a Soldier" matches the exuberance of its titular sociopathic soldier in music/
Patrolling the world with your little boy face And a grown up gun that shoots You've got a fresh scrubbed teenage outlook on terror And a khaki attitude.
Elite Agent Rotor in Dino Attack RPG. When he's not mercilessly blowing his enemies to kingdom come, we see him threatening to execute his own men and torturing prisoners.
Ronald E. Army is a somewhat darkly comedic version which combines this with Drill Sergeant Nasty. Of course nobody really takes him seriously and, considering his inspiration is clearly insane.
The sample group, "Bad Company" from the New World of Darkness sourcebook, Dogs Of War, are a bunch of Shell Shocked Veterans deployed to Afghanistan, led by Colonel Kane. Having had his heart cut out by a Taliban sorcerer, Kane has thrown the rulebook away in the interest of tracking down the sorcerer... and, incidentally, killing every Afghani who gets in his way. Several other examples are given (especially that one Chechen resistance group), but Bad Company are the standouts. If you're playing a military setting and don't alter your Morality accordingly, it's very easy for any Soldier character to fall into this.
The requirements for a Space Marine involve "a near-psychotic killing instinct". Granted, this is40K, so it's not like it's uncommon.
Even worse is that to the Orks, it's not even sociopathy, it's fun, war being to them a combination of jihad, mass migration and pub crawl.
The "Kanonen-Song" from Die Dreigroschenoper has a refrain about soldiers turning people into beefsteak tartare.
Specifically, people with darker or lighter skin than the British Army. They're equal opportunity racists.
In the Xbox/PS2 game Shellshock, there are numerous times where your squad massacres civilians even if you don't take part in it. In the second mission, you go to search a village for weapons and a single Vietcong. Or, after you round up everyone in the village, you can start shooting and the others will join in and gun down all the villagers, accomplishing the same objective. Later on, you also kill wounded amputees in a Vietcong hospital. Plus, one of your squadmates (whose name is literally "Psycho") constantly kills POW's in cutscenes, and helps the South Vietnamese commissar torture people.
Sabres Of Infinity Cazarosta, his hatred of the Antari, indifference to the horrors of war and his casual disregard of the rules of engagement amount to this.
Also committed by the HECU Marines/Army in the original Half-Life. While, to be fair, they ARE under orders to silence everyone, a few seem to take an unnecessary glee in their task. Somewhat averted in Opposing Force - the game sets up events so it's extremely hard to get any surviving military member to meet a scientist (and if he does, said scientist is dead), but for the most part, they're more concerned with getting out and saving each other. Black Ops, on the other hand...
Evil Soldier: I killed 12 dumb-ass scientists and not one of them fought back! This sucks!
Good Soldier: I didn't sign on for this shit... Monsters? Sure. But Civilians? Who ordered this operation anyway?
How a lot of the opposing grunts are portrayed in SOCOM US Navy Seals - but the few that you get the drop on in conversations casually talk about what their former base used to be, complaining about their Straw Feminist of a CO, or recruiting civilians onto their side with idealistic logic.
Something similar happens in Metal Gear: Ghost Babel, although that one does involve the players actions (kind of, although Pyro Bison's overall message is the same, the number of enemies killed changes depending on how many the player actually killed, with two being the absolute lowest due to there being no alternative for Slasher Hawk and Marionette Owl.)
Colonel Cobar from Killzone: Liberation. When he was still a private during the formation of the Helghast military, he shot his military instructor for stopping a training operation because another recruit was wounded. His ascension to colonel made it worse: mere days into the invasion of Vekta, he captured, tortured and dismembered three ISA council members in Sedah City.
Rico from the same series takes it up a step further, and apparently is a good guy. His questionable tactics include wielding a heavy machine gun during a hostage situation and not settling for stealth when Helghast can be killed. It gets bad in Killzone 2 when Templar decides in some strange fashion that he is worthy of not only heading up Alpha, but also getting the charge to capture Visari. Guess how it ends. In the manual for the first game, it's stated he was a Rhino Squad member, who were known for being unnecessarily violent.
If God had wanted you to live, He would not have created me!
I joined this team just to kill maggots like you.
You were loud and ugly and now you're DEAD! Amen.
The majority of the team could be considered sociopathic soldiers, with some exceptions such as the Engineer (who is unfazed by most things) and the Sniper (a Consummate Professional; he even provides the page quote).
Lampshaded with the Sniper, who prides himself as a professional assassin, so he's not crazy, per se. His parents think so, however.
Sniper: I'm not a "crazed gunman", Dad, I'm an assassin! Well, the difference being, one is a job and the other's mental sickness!
The Pyro takes this further - even the other mercenaries regard him/her/it as being wildly socipathic. Just about the only intelligible sound he (let's just go with that for posterity) can make is a maniacal laugh as he burns everyone around him to death. His Meet The Pyro video revealed him to be far beyond mere sociopathy, and is actually completely divorced from reality all together.
Heavy: I fear no man...but that thing...it scares me.
Scout: I ain't talking to you about that freak, alright? He...He's not here, is he? How do I get this fricking thing off ?! *knocks down camera*
Spy: One shudders to imagine what inhuman thoughts lie behind that mask...what dreams of chronic and sustained cruelty?
Pyro's Mind: *A colorful Sugar Bowl land while Loving Spoonful's "Do You Believe In Magic" plays in the background
The Beast from Advance Wars: Days of Ruin might not seem like one, but Caulder addresses him as "Sergeant" at one point before noting that he no longer considers himself military. The implication is that the Beast was always the hateful, kill-crazy man he became After the End, and the only difference is that he no longer has the chain of command to hold him back.
Pretty much all of the Sith Troopers in Knights of the Old Republic, but the students at the Sith Academy on Korriban particularly stand out in that they basically spend their time showcasing their sociopathy in the hopes of being noticed by thir superiors. Mandalorians also count, including Canderous in your party.
U.B.C.S. SergeantNicholai Ginovaef of Resident Evil 3: Nemesis, an ex-soldier turned mercenary is this trope to a "T", plotting to murder all of his colleagues so that he can receive their pay. He's also a Badass Normal who somehow manages to survive the game, making your life a living hell the entire time. U.S.S. team leader HUNK, alias "Mr. Death", of Resident Evil 2 is a totally cold-blooded version, who willingly leaves his teammates to die in furtherance of his mission, and doesn't care at all about the civillians his team guns down.
Generally speaking the Umbrella Security Service (U.S.S.) and Umbrella Bioweapon Countermeasures Service (U.B.C.S.) seem to attract a lot of these guys. Given the nature of the work and the fact that most of them are Former Regime Personnel or professional mercenaries this unsurprising. The entire business his headed up by Colonel Kilgore Sergei Vladimir.
Vile from the Mega Man X series fits this trope to a T. Because of an irrepairable short-circuit in his brain, he absolutely LOVES destroying Mavericks, and even moreso causing as much collateral damage as he can while retiring Mavericks, which was partially the reason why he ended up being branded a Maverick himself later on (the other being his rebellious attitude towards his superiors).
An almost uniform trait of Caesar's Legion in Fallout: New Vegas. Rape, pillaging, enslaving and burning are standard procedure. Legionares despise weakness and will kill anyone who doesn't serve the Legion - soldiers, civilians, women, children, old people. What we call war crimes, they call tactical maneuvers. Their top field commander slaughters his own troops to keep them in line. Even Caesar himself, who is regarded as a godly figure by his troops and is trying to build a better world, is sadly aware that his Legion has yet to become more than just a horde.
Blackwatch from Prototype. The regular Marines in Manhattan view them with disgust, rightfully so; several Web of Intrigue memories show them murdering civilians for the hell of it. And laughing.
Mass Effect: Depending on how you play the game, Commander Shepard can be one of these, especially with the Ruthless background in Mass Effect 1. Deconstructed by the third game, where continuing to play this character type means you have to deliberately stab several allied characters in the back, most particularly Mordin Solus.
Medal of Honor (2010 version): Voodoo is a very self-restrained version. He doesn't kill anyone he shouldn't, but he does give it serious consideration on more than one occasion. His teammates make sure to tease him for this.
Captain Martin Walker from Spec Ops: The Line is a type 4. After the White Phosphorus incident that happens early on in the game, Walker goes from being a sensible soldier to slowly cracking under the pressure and becoming a raving madman with a hero complex. How quickly he does so depends on the player in some instances.
In Homefront the Korean soldiers spend the first few minutes at the beginning of the game brutalizing American citizens. A group of them shot a couple in front of their own child, and the Resistance see that the Koreans are killing the prisoners and burying them in mass graves.
Agent Jack Hunter, also known as Goldeneye. He's unique in that he's sadistic and careless—he wastes time hurting his enemies. MI-6 has no use for him, but SPECTRE, on the other hand...
Niko Bellic from Grand Theft Auto IV says he was surrounded by people like this in the Serbian wars but he himself is not one (although a lot of the blood he shed went beyond what was required in the line of duty, which disturbs him).
Most of the grunts in Schlock Mercenary fit this fairly well, minus the rape. When hiring new recruits, Captain Tagon even commends his senior officer Thurl for "hiring those [violent sociopaths] right up." To further the trope, most of the ones who get promoted beyond Sgt. happen to be a bit more rational in their thinking, with the notable exception of now-Lieutenant ShorePibald.
In the Transformers mythos, it's harder to list a Decepticon or Predacon who doesn't fit this trope than one who does. Though, seeing as the faction was founded by a sadistic madman and his like-minded followers, it's not hard to see why.
Even the occasional Autobot or Maximal fits, though they are usually only tolerated if they are especially effective. Even then, they're kept on a short leash.
Deconstructed in Avatar: The Last Airbender . Katara goes after the soldier who killed her mother, expecting a Psycho for Hire. What she gets is a cowardly old man, whom she angrily describes as "just empty. There's nothing inside you." The implication is that fear got him to act like a Type III in the field; outside of combat he's not much of a threat.
Another implication could of been that either that: the soldier was a Might Makes Right kind of guy, so he whimps out at the sight of more powerful figures (For example: his mother, and Katara). Or that he is a foil who shows that this (being a wimpy, cowardly, "Well Done, Son" Guy) is what Katara would have been like if her mother was still alive.
Yet another interpretation, is that he was a monster, but had some kind of crippling mother issues aside, and that years of retirement living under his mother had ground him down to the point that he wasn't worth killing. Or that he became that way as a result of the things he had done on the battlefield, becoming a Shell-Shocked Veteran.
The Simpsons implies that Homer Simpson, had he actually been on a battlefield, would have been of this trope. When he has to be an army recruiter, one of the things he is asking people in a failed attempt at recruiting them is whether they want to kill people. Also, in "You Kent Always Say What You Want," Homer compares his elation to getting his 100th ice cream cone as being similar to gaining his first kill had he been in a war. Mitigated when he was once recruited by the Marines, he isn't smart enough to even hold a rifle, the one they gave him only shoots bubbles.
Every war, ever, has examples of this show up on all sides. Some have more, some have less, but no one has none. The amount varies widely depending on a whole range of factors, with the most important one usually being whether such behavior is shunned, ignored, or outright encouraged by military higher-ups and politicians (with countless examples of all three options). Scientifically tested here, especially the second page. Also, relatedly, this article.
This video seems to go more in depth about the first kind.
The Thirty Years' War (1618-1648) produced thousands as mercenary armies pillaged for three decades across the length and breadth of Germany.
The Phoenix Program of the same time seemed aimed to create thousands of examples of this trope for the war effort, with tens or even hundreds of thousands of victims, alive or dead.
This breed of soldier seems to be very common in Colombia's various military/paramilitary organizations. As theWar Nerd puts it: "They kill in uniform or out, home or away, on the street or the battlefield. Equal Opportunity Slaughter: men, women, children, dogs — if it moves, they'll kill it. For any reason. For no reason. For money, for fun, for the Revolution, for the Counter-Revolution, for practice."
Many examples, Type 1 and 2, from Argentina's Dirty War, which took place from 1976-83. Under the junta, torture, kidnappings, and mass murder were institutionalized, and carried out by members of the Argentine armed forces. Some, such as AdolfoScilingo have repented, and asked to be imprisoned. Others, like Julian the Turk have not, and indeed seem very proud of their achievements. At least 30,000 people were killed, by leaders who claimed to be protecting them from the Dirty Communists.
General Iberico St. Jean, governor of Buenos Aires: First we will kill all the subversives; then we will kill all their collaborators; then their sympathisers; then those who remained indifferent; and finally, we’ll kill the undecided.
If you read his interview with a reporter just before a nasty incident that landed him in prison, he is a Type 3 example.
Italian,and Belgian soldiers were caught abusing Somali civilians during the peacekeeping and humanitarian operations there in late 1992/early 1993. The Italian soldiers also photographed what they did, with methods of torture and abuse comparable to Abu Ghraib a decade later.
A group of U.S. soldiers were recently put on trial for deliberately killing Afghani civilians and planting evidence to make it look like self-defense. Not only that, but they also threatened several members of their unit that might have told in order to keep them quiet. Threats included purposefully dropping a weight on them while lifting weights.
Spanish "Conquistadors", there are chronicles of them (from a Spanish priest, no less) that tell how they would rip children from their mother's breast, cut them while still alive and feed them to the war dogs.
Enlisting in the armed forces has become popular among white supremacists and inner city gangs who hope to acquire knowledge of military tactics which they could apply in their criminal activities. The problem has gotten so severe that recruits are now examined for gang tattoos that might identify a past or present association with said groups, and more than one tattoo, gang-affiliated or not, is grounds for being barred from recruiting.
As in the case of Argentina's Dirty War, Guatemala's long, long civil war (1960-1996) produced many of these, as the military junta became more and more brutal in its dealings with the populace. Soldiers carried out acts of mass politicide, and ethnic cleansing and genocide of the indigenous Mayan population became a feature of the war. Of the 200 000+ people who died in the war, over 90 percent are believed to have died at the hands of the Guatemalan Army; this does not even include the 45-50 000 people who were "disappeared". To pick one particularly gruesome example at the village of Los Dos Erres, the army buried civilians alive, dashed the heads of infants against walls, and kept the village's women as prisoners so they could repeatedly rape them. The soldiers involved ran the full gamut of types, from I-IV.
During Brazil's military dictatorship, the soldiers would torture dissidents. By itself that makes them sociopathic. Wait until you learn that they also tortured THE BABIES of dissidents. A fine mixture of types 1 and 2, with a nice little dash of Moral Event Horizon.