Sudden Principled Stand

"With all due respect, sir, I was not trained to murder the innocent."

- Phoebus in The Hunchback of Notre Dame

Things are not going well. Everyone around you gets more cynical and less caring for each day: It Gets Easier. What started out with good, or at least neutral, intentions, ends up more self-serving or antagonistic. The descent has been so slow and so drawn out in time that is has just crept up on everyone.

Then! Someone says "Enough!", usually surprising everyone around them, and makes them remember why they are really there, or what they used to be. This can be in a confrontation with someone in a position of authority, who finally is coming too close to dragging themselves and everyone else over the Moral Event Horizon, but it can be triggered by other factors as well. The Sudden Principled Stand can of course also be done with only two people present, the one giving the order and the one refusing.

The Sudden Principled Stand takes parts of its drama from its suddenness—it might very well be planned, but its execution comes as a surprise for the people around it, who earlier had been given no hint about it.

One common variation is that the principled stand hinges on a very minor technicality, in which case it is a Reconstruction of a one-off Obstructive Bureaucrat. Can also be combined with a Heel Face Turn, especially if late in the story. Earlier in a story, it can be used as an Establishing Character Moment, to establish a moral center, or establish a later conflict. The variant where the principles invoked are evil is of course possible, but likely uncommon.

Compare Neutral No Longer, Screw the Rules, I'm Doing What's Right, Rage Breaking Point (where anger is handled this way).

Anime and Manga
"Roswald: I'll teach you what happens when you assault us, the descendants of the world's creators! Sanji: Hell if we care, bastard."
 * Luffy - the protagonist of One Piece - isn't a villain (even if he isn't exactly a hero) but his actions at the auction house during the Sabaody Archipelago Arc clearly qualify. The World Nobles are an untouchable privileged class, given anything and everything they want by the World Government. Harming them is a war crime. But when one of them - Charloss - assaults Hatchan - not the first atrocity Luffy had witnessed - the Straw Hats captain just didn't give a damn anymore, and gave Charloss the thrashing he deserved.
 * AND, after he did so, Zorro comments that had Luffy not taught the guy a lesson, he would have. The rest of the crew follows suit, especially when Charloss' equally-jerkass father Roswald doesn't know when to quit:

Comic Books

 * In the Black Orchid miniseries, the second Black Orchid, after one of Lex Luthor's operatives, Sterling, tracks her down to the Brazilian rainforest, refuses his ultimatum to accompany him peacefully to Lexcorp for anatomical study. Sterling orders his two Mooks to kill her with herbicide. However, awed by her beauty and that of the surrounding ecosystem, they refuse ("I--we've killed for you before. It's what we do. But not her. Not here."), and he returns to Metropolis empty-handed. Foreshadowed in that one of the mooks, en route, discusses what he's read about the endangered Amazon rainforests.

Film

 * In The Apartment there's Bud's climactic refusal to let Sheldrake use his apartment for a tryst with Fran after her.
 * Phoebus against Frollo in The Hunchback of Notre Dame, as quoted above.
 * In Lion King 2 Vitani refuses to attack the Pridelanders even when ordered by Zira, because she was convinced by Kiara's heartwarming speech. In response, Zira threatened that Vitani would die as well. In turn, the rest of Zira's followers refused to attack the Pridelanders.
 * In Kung Fu Panda 2, Boss Wolf refuses to fire upon the heroes with his own men in the crossfire. Shen responds by killing him on the spot.

Literature
""She's Commodore Vorkosigan's prisoner. Sir.""
 * In the opening of The Shadow of the Lion, Abbot Sachs has, with the help of several Knight Templar, apprehended some children in a church, that he claims are enacting satanic rites. Erik reminds the knights that the kids are most likely innocent, have sanctuary in the church, and can only be removed by order of the parish priest. This sets up Erik as a moral center for the knights, and a conflict with the abbot.
 * The Vorkosigan Saga by Lois McMaster Bujold has several examples:
 * In Falling Free, Bannerji doesn't refuse to fire at and destroy the ship that the Quaddies escape on per se, but he demands a proper work order, signed by the Hazardous Waste Management Officer, and with an Environmental Impact Assessment attached. This gives the ship time to escape.
 * In Shards of Honor, when Sergeant Bothari refuses to rape  as per Admiral Vorrutyer's orders.


 * Deryni Checkmate: The day after the Curia excommunicated Morgan and Duncan, its leaders, Archbishops Loris and Corrigan, tried to push through an Interdict on Morgan's duchy as well. The previously neutral Bishop Cardiel spoke against the measure, precipitating a schism within the Church. Cardiel argued that it was unjust to punish the people of Corwyn for the actions of its duke and left open the possibility that Morgan and Duncan were morally innocent. The conflict escalated as other bishops, including Arilan and Tolliver (Corwyn's bishop) joined in, accusing Loris of supporting a rebellion against the king and promoting genocide against the Deryni.
 * The entire plot of 1812: The Arkansas War hinges on this trope, in that the United States is forced to address slavery in the 1820s instead of the 1850s, and in a far more direct way. It's not too sudden, but then it involves an entire nation.

Live Action TV
"Cpl. Coltrane: "This has got to stop!""
 * In Torchwood: Miracle Day, Cpl. Coltrane starts off as little more than Colin Maloney's cringing accomplice as he . In episode 6, however,.


 * A form of this occurs in "The West Wing." In the 6th season, a conservative Senator is trying to attach a rider banning gay marriage to a budget bill. Toby is looking to rally support, and goes to the Vice President, Bob Russell, for a statement of support. Russell, who is widely regarded as an idiot, mildly corrupt, and a bit of an opportunist, surprises Toby by refusing. Russell states that he has a gay nephew, but is against gay marriage because "it could set back progress fifty years."

Western Animation

 * Lion-O from ThunderCats (2011) takes one against a blood thirsty mob and his own father.
 * Gillecomgain from Gargoyles is a rare villainous example: He had no compunctions about killing Macbeth's father or marrying Macbeth's girlfriend (both on Prince Duncan's orders), but when Duncan ordered him to assassinate Macbeth himself as well, he refused for pragmatic rather than moral reasons: "Nay, milord. Macbeth is an heir to the crown, and much beloved by the people; besides, it might lead to some uncomfortable questions about his father's demise... and who demanded it."