2112 AD. Islamic terrorists have destroyed Los Angeles, Kansas City, Boston, and London with nuclear weapons, and several other cities avoided total destruction due to malfunctioning weapons. After being elected in a campaign whose entire focus is "we're gonna get them" (the "them" later proving to have a rather broad definition) the new president launches nuclear missiles at most of Islam's holy cities. The Islamic lands took a long time to recover under a new Caliphate. Meanwhile, the surviving Muslims, through heavy immigration and far greater reproduction rates, take over most of Western Europe save Britain and Switzerland. With a liberal Europe melting away to the Islamic threat, it submits and becomes the Caliphate of Europe and Western North Africa. A strict Sharia law was imposed, many of the boys being forcibly converted to Islam through the Janissary program, and the remaining Christians being made to pay the Jizya, a head tax on non-Muslims. In this background a German girl named Petra bint Minden was sold into slavery, her brother Hans taken to the Janissary corps for training. However browbeaten, she has always dreamed that someday she will escape this living hell through a diary passed down from her great-grandmother.

Meanwhile, the United States has mutated into an Empire, authoritarian as it gets, and it encompasses most if not all of North America, some territories in South America, and the Philippines, where John Hamilton, a US Army officer, goes to a brief breakdown after his fellow Army officer and girlfriend, Laurie Hodge, was killed in a firefight between US and Filipino forces and Muslim rebels. He accepts a transfer to the CIA, now renamed the Office of Strategic Intelligence, where he becomes an officer and he is tasked to infiltrate the European Caliphate to capture or kill renegade US scientists making a super-virus intended to kill millions and to advance the Caliphate's cause. And so Petra and Hamilton's paths cross in an effort to save the world, and to ensure Petra's freedom.

Caliphate was written by Creator/TomKratman, the same author of the ''Literature/CarrerasLegions'' series. As it such, it was charged with political intrigue and posits a dystopic and controversial future.

The novel is available for free from [[Creator/BaenBooks the Baen Free Library]], without any DRM restrictions, [[http://www.baenebooks.com/p-748-caliphate.aspx here.]]

!!Caliphate provides the examples of:

* BalkanizeMe: It is implied that the Indian subcontinent broke into many parts.
* BigDamnHeroes: The Swiss Air Force, moments before [[spoiler:the Caliphate airforce blasts the airship full of child slave escapees and the world infecting virus.]]
* BlackAndGrayMorality: The Imperial States of America isn't exactly a shining "white hat", but as presented in the novel it's a better option than the Caliphates (particularly the one on which the novel is focused), who are very much of the "black hat" persuasion. The other nations that get any attention aren't much better than the ISA.
* CampGay: Lee, Ling's Chinese control officer.
* {{CIA}}: Now called the Office of Strategic Intelligence after a reorganization and purge.
* CrapsackWorld: Much of Continental Europe is under decay under Caliphate rule. The Middle East is a crapsack state as well, as noted by character Besma. Occasional postapocalyptic Muslim raiding parties strike out into Russian controlled territories. Russia has a socialist Tzar who holds his Muslim majority under an iron fist. South Africa has a darker Apartheid (this time with genuine black slavery) after embittered European Refugees filled it. China is a strange posthuman empire which breeds genetically engineered women to infiltrate the Caliphate. Fuel is strictly rationed and most cars run on methane engines, and stink to hell. Mass transit is the only way to move around, and the Caliphate's infrastructure is reduced to horse-drawn carts for Christian dhimmi and methane-stinking cars for rich Muslims. The United States? A new Roman Empire whose soldiers commit horrid atrocities because the enemy would do much, MUCH worse. The first combat scene we read has a group of Muslim Philipinos (Moros) raping and torturing captives to death, only to be caught, shot, their DNA analysed and everyone back in their village with matching DNA killed Einsatzgruppen-style. Some of the American soldiers actually laugh, sing and celebrate the executions, and they are "genuinely" the only stable guys in the story (even from a neutral point of view). That should give you a general idea of the setting.The rest of the world isn't much better, with everyone pretty much in a state of hostility to one another that's effectively low-level war punctuated by periods of actual armed combat. Even Switzerland is a gigantic armed camp surrounded by the Caliphate.
* DirtyBusiness: Hamilton despises having to take on the role of [[spoiler:a child slave trader]], but goes through with it anyway in spite of his detestation of the institution, due to the seriousness of the situation that caused the mission in the first place.
* DisproportionateRetribution: In the backstory, even though only three nukes were successfully detonated, President Buckman literally razed the Middle East and North Korea with at least a hundred nuclear warheads. The US then invaded Saudi Arabia to secure the oil fields there. When said oil ran out, the US forces left and destroyed the oil field facilities with nuclear weapons, literally crippling the Middle Eastern economy for decades to come. Also, in the book, for supporting Moro rebels in Philipinnes, the Imperial American air force razes entire Malayan cities to the ground.
* DrowningMySorrows: On the first days of his mission when he was visiting South Africa, Hamilton wishes that he could get totally trashed over his cover job [[spoiler:of a child slave trader]], but can't afford the resultant loss of control in what's effectively "enemy territory".
* EnemyMine: In spite of a continuing state of low-level conflict between them, the ISA and the Celestial Kingdom of the Han (China) work together to eliminate the threat posed by [[spoiler:the Caliphate's bioweapon.]]
* ExpandedStatesOfAmerica: The US expanded into North America and the Philippines. They even had ''Scotland'' as an Imperial Province!
* TheFatalist:
** Pretty much all Muslims, even those like Mahmoud al Beshay who left their homeland to get away from Islamic culture, believe that something will or won't happen depending on Allah's will. [[spoiler:Up to and including surviving an incredibly nasty bioweapon the Caliphate is having created to wipe out their enemies.]]
** One of the reasons the Caliphate relies on the Janissaries for their military forces is that the Janissaries will practice and perform regular maintenance on their equipment so that it remains functional, as not being raised from birth in Islam means "as Allah wills it" isn't a core behavioral tennet.
* FunWithAcronyms: '''S'''uited '''H'''eavy '''I'''nfantry '''T'''rooper. Hamilton's pointing out the acronym was enough to earn him demerits in the Academy.
* GeneticEngineeringIsTheNewNuke: The Caliphate's [[spoiler:[=VA5H=]]] virus is an engineered bug, intended for use as a DepopulationBomb.
* HeroicBSOD: Hamilton suffers through this when Laurie was killed in a battle in the Philippines.
* ILetGwenStacyDie: Hamilton having to give the order to bomb the position where an already-wounded Laurie Hodge (his girlfriend) was surrounded by Filipino Muslim rebels and about to be raped is enough to push him to leave the military.
* ImpaledWithExtremePrejudice: Rustam, one of the instructors of the janissary group that included young Hans, says he hates the Greeks and Serbs, thanks to many of his fellow soldiers having been staked, [[GroinAttack castrated]], and [[EyeScream getting their eyes gouged out]] when fighting in the Balkans.
* InfoDump: Several places throughout the book, but the ''Excursus'' in Chapter 9, an excerpt from a fictitious nonfiction work about how the USA became the ISA, outlines how President Buckman came into power [[spoiler:after three US cities (Los Angeles, Kansas City, and Boston) were destroyed by nuclear weapons deployed by terrorists, and four more cities (Houston, Washington DC, Chicago, and New York) escaped a nuclear holocaust due to being targeted with defective devices.]]
* IstanbulNotConstantinople: Europe has morphed into the European Caliphate in the 2100s. As a result, many places' names were corrupted if not outright changed. Like Baya for Bavaria, Grolanhei for Grosslangheim, Affrankon for Franconia, Slo for Oslo, among others.
* MedalOfDishonor: The Martinez Award, given by [[MilitaryAcademy West Point]] to the cadet with the most demerits without having been kicked out. Hamilton himself doesn't consider it something to be proud of, but the Sergeant that he reports to after leaving schooling treats it as a genuine badge of honor, figuring that nobody who doesn't have what it takes could piss off so many people without having been kicked out of the Academy.
* TheMole: Ling, a Chinese agent sent into a brothel where Petra was working. She also becomes a big sister figure for Petra and aids her cope with living.
* ObligatoryWarCrimeScene: Moros roasting captive Americans alive, Americans killing said Moros and their DNA-tracked families, then razing every city that send Moros arms. Boer slave farms where black kids are separated from their mothers, and crucifixion scene of every Dhimmi that commits a crime. The book bulges with every war crime imaginable, and openly states that the American side laments the destruction of liberties associated with the war.
* MiddleEasternCoalition: While the core Middle Eastern lands do become a Caliphate, it does not take part of the story. And with [[CrapsackWorld good reason]].
* NobleBigot: Adbul Mohsem might be a slave-owning Muslim in Germany, but he does care for dignity of life of even lowest of slaves: setting them free after their effort and labor reaches their purchase price (even then with a discount), and doing his damnedest to care for/repurchase the poor Petra who gets in legal trouble. The worst thing he did to her own daughter Besma was an impulsive, low strength slap at her boast of "she'd lay with everyone if Petra is sent away, from slaves to infidels"
* NuclearOption: The US President reluctantly was pressured by the Secretary of State and Defense to use nuclear weapons on Castle Honsvang in Germany, where the hideout of three rogue US scientists are hiding to make a powerful virus in case Hamilton fails.
* ThePardon: President Buckman, in the backstory, uses the power of presidential pardon as a weapon against Americans he politically opposes, pardoning all but one person who murdered his opponents (the exception was due to the murderer having been determined to have killed purely as revenge for an affair between the victim and the killer's wife, and nothing to do with politics).
* OurPresidentsAreDifferent: President Buckman, from the backstory, is President Insane and a PresidentEvil who eventually became TheEmperor (in name if not formal title) as the United States of America turned into the [[TheEmpire Imperial States of America]].
* PeoplePuppet: There are chips that can be implanted in a person's head that allow the person so equipped to be operated remotely, [[spoiler:as is done with Bernie Matheson and Zheng Ling]]. It used to be required that ISA agents get one implanted until the Chinese demonstrated how they could be hacked, much to the worse for the ISA. Chip security was improved, but there still remains a strong aversion to "chipping", as the implantation procedure is called, among ISA agents.
* PoweredArmor: Not in the traditional sense, in that the suit itself is more of an armored exoskeleton, but the ones worn by the Suited Heavy Infantry can have armor added to them to increase their protection, or reduced to enhance speed and endurance. It's explicitly pointed out when they're introduced that they do not make the wearer invulnerable, just that the user requires more effort to kill.
* ShoutOut: One of the historical works quoted in the series is a ficticious nonfiction work published by [[Creator/BaenBooks Baen Historical Press]].
* SlaveMooks: The janissaries are young non-Muslim boys taken from their families and brought up in Islam to serve as the Caliphate's armed forces, much like the RealLife version that served the Ottoman Empire.
* StrawmanPolitical: Most leftists are portrayed this way.
* UnitedEurope: Subverted, it [Western Europe at least] becomes mostly Islamic. The British Isles and Switzerland are not under Islamic control. Russia is implied to control Eastern Europe.
* TheVirus: the three renegade US scientists led by Claude Meara made a particularly potent flu virus [[spoiler:called [=H5NV=]]]. It was designed to die out after two generations, but for some reason it can't, and it turned out to be more dangerous than first thought. Fortunately, Hamilton and Bernie retrieved the sample in time to make a vaccine out for it.
* WeaponOfMassDestruction:
** The titular Caliphate has hired several American scientists to create a bioweapon to wipe out their enemies, without any concern for who else -- including themselves -- that would be harmed [[spoiler:by an engineered virus that's 97% fatal -- and possibly mutilating the remaining 3%.]]
** In the backstory for the book, Islamic terrorists deployed nuclear weapons against the cities of several western countries, including the US and the UK. The three that detonated in the US[[note]]the other four targeted on US cities failed to detonate due to poor maintenance[[/note]] were sufficient cause for the election of [[PresidentEvil President Buckman]], who later nuked almost all Islamic holy cities in retaliation for the various attacks on the US over the years.
* WickedStepmother: Al Khalifa is a revolting bitch who's jealous that a girl (Besma) birthed by a slave was in line to inherit Abdul Mohsem's wealth over al Khalifa's own son. She agreed to allow her husband to purchase Petra because while al Khalifa couldn't harm Besma, as Abdul's cherished child, she ''could'' harm a slave without consequences. Eventually she is divorced and gets sold to a brothel. Laser Guided Karma indeed.
* ZeppelinsFromAnotherWorld: Given the relative scarcity of oil but plentiful energy thanks to nuclear power, hybrid lifting body airships powered by pebble bed nuclear reactors are the most common mass transportation for both civilian and military purposes in many countries.