Won the War, Lost the Peace in Literature.
- Arcia Chronicles: In the second duology, based heavily on the Wars of the Roses, Alexander (Richard III's expy) wins the war against Ifrana (France) for his royal older brother Philip (Edward IV), but Philip then signs a strategically poor peace treaty (Treaty of Picquigny) with King Joseph (Louis XI) that gives large momentary gains to Arcia and more than enough time to prepare for retaliation to Infrana. What's more, it does a great job estranging Alexander from Philip.
- Lord of Light has an inversion. The protagonist loses the battle of Keenset, but as an eventual result of it, his "Accelerationist" viewpoint that technology should be shared wins the day over his opponents' "Deicrat" viewpoint that this is dangerous, as the battle weakens them enough that they can't maintain the same level of strict technological control as they were accustomed to.
- John Christopher's The Tripods trilogy ends with the group defeating the Tripods, and then having to try to tame humanity itself.
- Brandon Sanderson's Mistborn trilogy is based on this. In the first book, they defeat the Evil Overlord. In the second and third books, they deal with the consequences.
- In Honor Harrington, the ceasefire between the Star Kingdom of Manticore, led by High Ridge government and The People's Republic of Haven, led by Oscar Saint-Just, is an example for Manticorans. Despite being on the brink of total military victory, the new government following an assassination accepts Saint-Just's proposed ceasefire, then drags on the "negotiations" for several years, in the process screwing up their own military and giving the next Havenite government plenty of time to build up their military, catch up some technologically, and get good and pissed off that Manticore is stringing them along. When the war inevitably restarts, it starts with Haven at a huge advantage. They ultimately make peace and sign a military alliance thanks to the discovery of a common enemy and the most audacious diplomatic gambit ever seen in the series — and by "diplomatic gambit" we mean "the President of Haven shanghaied most of her Cabinet and paid an entirely unannounced call on the Queen of Manticore" — but not before a cataclysmic attack on the Manticore System guts both navies and leaves hundreds of thousands dead.
- The Witcher: The Elves are against the Northern Kingdoms who oppressed them and broke their forces in a war centuries ago with Nilfgaard, first as guerillas
, then openly. When the Emperor finished his conquest, he gave them a little independent state as promised, but naturally this enclave was a weak partner of an overlord whom they couldn't oppose in any way, humans in all affected lands switched from occasional prejudice to deep hatred and... the peace was marked by delivering the most aggressive ones to the offended sides — who didn't just immediately execute them. - A Song of Ice and Fire:
- This ends up biting Robb Stark in the ass hard. He wins every battle he leads against the Lannisters, but dealing with his own bannermen is a hell of a lot harder, especially after he chooses to disregard his oath to one of them to marry his daughter, having fallen in love with another. This eventually results in him getting stabbed in the back.
- This is essentially what happened to Robert Baratheon after the Robert's Rebellion was over and he was crowned king of Westeros. A decent general and a great leader, but a lousy administrator and politician, it was only the outbreak of another war (the Greyjoy rebellion) that allowed Robert to actually consolidate his grasp on the throne. Control of the Seven Kingdoms slipped out of his grasp due to courtly intrigues he did nothing to rein in, and upon his death his heir was left with only the Lannisters as allies while all the other great houses rebelled or stayed neutral. To his credit, Robert recognized this about himself." I swear to you, I was never so alive as when I was winning this throne, or so dead as now that I've won it."
- Daenerys Targaryen also deals with this after leading her own anti-slavery crusade through the cities of Slavers' Bay. Once she settles in Meereen, she hears stories of atrocities carried out in Astapor, the first city she liberated, and realizes that Meereen is in its own state of fresh chaos. She decides to put the whole "retake the Seven Kingdoms" thing aside until she can maintain some order in her new kingdoms, first. She explicitly considers this a training run so she can get a handle on what she's going to do later; and, both as expected and as a result... things go badly. Turns out that treating real people, places, and problems as simple practice for "the real thing" adds up to a lot of half-baked "solutions" primed to blow up in your face in record time.
- Even the Lannisters suffer badly from this. They may have nominally 'won' the War of the Five Kings, but by the time the war reached its conclusion, Joffrey, Tywin, and Kevan are dead, Jaime is maimed, Myrcella is disfigured, Tyrion has been driven into exile, and the recently humiliated Cersei was left alone to govern for her weak-willed young son Tommen. By the end of Dance of Dragons, the Lannisters are under attack from an enormous Greyjoy fleet, the remnants of Stannis Baratheon's army, and Aegon Targaryen returned from exile. There is a strong possibility of Dorne, Daenerys, and the Others joining this list. All this while winter has come and their alliance with Highgarden grows more and more fractured. Their main allies in the Riverlands, the Freys that they put in position as Lord Paramount after outwitting House Tully, are also hated by their new vassals and are killed at every opportunity due to their role in the Red Wedding, with no one respecting them or submitting to their authority.
- The civil war known as the Dance of the Dragons ended in this. The Green faction, lead by Aegon II, managed to capture Dragonstone, kill the Black leader Rhaenyra I, and capture her son and heir apparent (later to become Aegon III), but not only was he grievously injured in the process, his brutality against Black lords also led them to keep the war going until Aegon's own courtiers poisoned him just to make it stop. Rhaenyra's son then took the throne, vindicating her dynasty even if not her personal claim to the throne, and both Rhaenyra and Aegon went down in history as usurpers and warmongering assholes.
- The Lord of the Rings:
- The downfall of Númenor as described in the appendix. The Númenóreans assemble a mighty army and invade to attack Sauron. Sauron surrenders and is carted off in chains to Númenor, where he becomes Ar-Pharazôn's evil counselor, egging him on to attack Valinor. This does not go as plannednote ...
- The Third Age prior to the main events of the books is a three-thousand-year version of this. The Last Alliance defeat Sauron at the end of the Second Age, but Isildur fails to destroy the Ring, which leads to the estrangement of Elves and Men and his untimely death, which itself causes the split of Arnor and Gondor. Arnor ends up fragmenting into smaller states and slowly being gobbled up by Angmar, with the Elves only helping when it is destroyed, while Gondor spends centuries fighting the Easterlings, Haradrim, and itself, leaving it a shadow of its former self by the time Sauron rolls round again.
- Machiavelli points out in The Prince that a Prince who won a war and wants to avoid being perceived as cruel will leave the opposition alive. This inevitably concludes in a later war, disorders, and a lot of people dead. So, the paradox is that a Prince who truly wants to win the peace must crush the opposition (but not the general populace) fast even when the war has already been won, so all their subjects cannot see any hope in opposing their new ruler, and don’t waste time and effort trying it and truly accepting the new peace.
- Referenced in Guards! Guards! as a common problem of revolutionaries. One minute everyone is cheering the overthrow of the tyrant, and the next everyone is complaining because nobody's picking up the trash.
- This is the main reason why no one's actually managed to overthrow Vetinari. They may not like him, but he runs Anhk-Morpork like clockwork.
- Happens in Heimskringla's "Saga of King Harald Hardrada", where Harald fails to conquer the Kingdom of Denmark, even though he is almost always victorious in battle against his rival Svein Estridson. The trope is lampshaded and discussed later by Earl Tostig of England in conversation with Harald when he points out that Harald's failure was solely because of his lack of favor with the Danes, who clung to the popular Svein in spite of defeat.
- In the World War books by Harry Turtledove, a group of aliens invade Earth in the middle of World War II. The aliens prove to be so politically naive and diplomatically inept that at one point Josef Stalin tells his Number Two Vyacheslav Molotov that as long as the Lizards cannot achieve complete victory in war, they will certainly lose during peacetime.
- He's proved right: by the time of the final book in the series (set forty years after the initial four books dealing with the invasion) Earth culture is invading the Lizards' one, their military position on Earth is weaker than ever, and the US, having developed FTL travel, have technologically outpaced them.
- The novel Xala by Senegalese author Ousmane Sembène is set just after Senegal gains independence from France, and satirises the failure of post-colonial African governments to improve the lives of their people.
- Brought up early in Maoyu as one of the Demon King's arguments for peace with humans. Even if one side were irredeemably evil and killing them was fully justified, in the aftermath their lands and resources would swell the influence of the most greedy and corrupt, while regions dependent on wartime trade would have their economies collapse and rebel, leading the winning side to tear themselves apart.
- The Treaty of the Iersen Bridge in A Song for Arbonne ceded all the northern lands of Gorhaut to Valensa in exchange for money, dispossessing a significant part of Gorhaut's population and squandering the victory in the actual Battle of the Iersen Bridge. The shameful deal motivates many Gorhautians: some want to restore Gorhaut's honour, others just treat it as opportunity to invade the titular Arbonne.
- Although the first war with Voldemort in the Harry Potter novels resulted in Voldemort's defeat and presumed death, many of his top followers were able to bribe their way out of prison and were quickly reestablished as pillars of the community. By the time Voldemort returned they were effectively running the government, making the Death Eater takeover pathetically easy once Voldemort finally decided to move.
- This is the focus of the second half of The Moon Is a Harsh Mistress. The rebellion overthrows the tyrannical Lunar Authority months earlier than they had planned to, and thus find themselves in charge with nothing in place to govern themselves. This forces them to improvise by, among other things, pretending to Earth that the Authority is still in charge so they don't send attack ships to end the new government before it can begin.
- In the Animorphs Spin-Off novel The Ellimist Chronicles, the Ellimist seeks to end a war between two planets by creating an impenetrable Asteroid Thicket between them, forcing the two sides to call off the war because their ships are no longer physically capable of prosecuting it. He returns after a Time Skip to discover that rather than end the war, the Asteroid Thicket gave one side the idea to plant Space Mines in the other planet's path, nuking the enemy into extinction. Suddenly without an enemy, they fell into civil war and ended up bombing themselves into a preindustrial state.
- The aptly-named Alternate History timeline Losing The Peace demonstrates this perfectly. While the United States successfully pacifies West Germany, the repercussions of the actions taken there cause a resurgence of the German-American identity, which turns violent during the 2nd Great Depression.
- The Combat Baker and Automaton Waitress: After the setting equivalent of World War I is won by Wiltia (Germany), they soon find themselves struggling to hold the country together, to the point where some officers claim that things were easier back in the war. This includes the recently-annexed Pelfe region coming to the brink of rebellion, the ruthless General Genitz taking control of the nation's Praetorian Guard and amassing resources to attempt a Military Coup, foreign assassins lurking around visiting dignitaries, and a series of treaties that place heavy restrictions on Wiltia's use of Lost Technology weapons (but not any Lost Technology that other nations may have dug up in secret).
- The French children's book Fattypuffs and Thinifers plays this extremely straight. The efficient Thinifers crush the indolent Fattypuffs militarily, but the amiable Fattypuffs are much better at dealing with people than the impatient Thinifers and eventually take over all the key jobs in the combined country.
- The second arc of The Lost Fleet series deals with the spectre of this trope hanging over the protagonist's home nation, and his increasingly desperate attempts to avert it because after literal decades of brutal war of attrition, the side that technically won is almost as battered and war-weary as their erstwhile enemies.
- Spin-off series The Lost Stars has many of the same themes, being set in one of the solar systems that played a brief but important role in the last volume of the main series. The main characters lead a successful coup and throw off the shackles of the Syndicate Worlds... in the first chapter of the first book in the series, Tarnished Knight. The rest of the four-book series is devoted to them figuring out how to build a functional government from scratch while fending off multiple unfriendly policies on their borders, while Planetary CEO-turned-President Gwen Iceni desperately tries not to fall back into bad habits and have the whole endeavour turn into a Full-Circle Revolution.
- The Dresden Files: Changes ends with Harry killing every member of the Red Court via a curse. He's not around to witness what happens next — which is that in the wake of the massive power vacuum he caused, a new faction steps out of hiding and starts moving to take over, causing a lot of trouble in the process. And once he gets back, he finds that he may have ended one war, but there's no peace now — just a whole new war to fight.
- A side plot in Trash of the Count's Family is dealing with the fallout of the civil war in the nearby Whipper Kingdom; its new leader is incapable of politics and only thinks about fighting, it lacks resources for the people in the recent end to the extremely draining conflict, and it has no allies to support it in the much bigger war that's to come.
- In The Arts of Dark and Light, the elves won the war against the Witchkings, but failed to capitalize on the victory politically. This, combined with their general exhaustion from the war and the heavy losses they suffered, led to the increasing decline of their surviving kingdoms.
- Osbert Grent of Grent's Fall may be great at combat and leading an army, but quite poor at ruling the kingdom.
