-> ''"Why, you may take the most gallant sailor, the most intrepid airman or the most audacious soldier, put them at a table together - what do you get? The sum of their fears."''
-->-- The book's preface, quoting UsefulNotes/WinstonChurchill.

''The Sum of All Fears'' is the fifth [[Literature/JackRyan Ryanverse]] book written by Creator/TomClancy. It was published in 1991, just days before [[http://en.wikipedia.org/wiki/Dissolution_of_the_Soviet_Union the Moscow uprising]], and takes place at roughly the same time, being the seventh book chronologically. Russian politics in the aftermath of the destruction of the Berlin Wall is a main element of the book.

The title is based on an anecdote recounted in the foreword: when you get a group of already hostile people together, their fears are amplified, to the point where the slightest misstep can set them on a course for war.

The story actually begins in 1973, during the Yom Kippur War. Israel, in its darkest hour, contemplates releasing its nuclear weapons against the Egyptian and Syrian armies, but rescinds the order once things turn for the better. However, in the chaos of battle, one of the fighters carries a nuclear bomb into battle and gets shot down, loosing its warhead into the countryside where it disappears.

Three years after [[Literature/ClearAndPresentDanger the drug interdiction fiasco in Columbia]], Jack Ryan is now the Deputy Director of the CIA, [[HypercompetentSidekick but is essentially the de-facto Director of Central Intelligence]]. He constantly bickers with the administration, especially the National Security Advisor Elizabeth Elliot. Meanwhile, the Soviet Union is falling apart, which no one is entirely happy about, and a new crisis erupts in Israel.

The book follows several factions, from Ryan and the CIA, to Andrey Narmonov, now the President of the Soviet Union, to Ismael Qati, a terrorist leader who discovers the missing nuclear bomb from the Yom Kippur War and is determined to use it to achieve his means.

[[Film/TheSumOfAllFears It was the fourth book of the series to be turned into a film.]]
!!The book contains the following tropes:

* AndSomeOtherStuff: In the afterword, Clancy admits to fudging "some" details of the workings and construction of nuclear weapons, in an effort to not help anyone with unkind intentions involving nukes (though he also acknowledges, if somewhat cynically, it probably won't actually stop anything).
* AuthenticationByNewspaper: The wife of one of the engineers working on the bomb is killed, to keep her from telling where her husband is. To prove that she's dead, they make a videotape of the execution, with a news program on the TV in the corner acting as a time stamp.
* BavarianFireDrill: The terrorists impersonate TV network service personnel to [[spoiler:get their bomb (disguised as a commercial VCR) into the Denver Skydome]]. Later, their German terrorist accomplices [[spoiler:get onto a Soviet army base in East Germany by donning Soviet officer uniforms, and pretending to be there for a surprise inspection]].
* BodyMotifs: A rather odd one, given the book's subject. If a female character pops up at any point, her naked breasts will be described or referenced.
* BringMyBrownPants: Played almost entirely straight (he just barely manages not to need them) when the explosives specialist in the terror cell realises that the mysterious object found in a farmer's field is not in fact an electronic-jamming pod as he'd first thought, having established that it's not a conventional bomb, but is actually a nuclear warhead. Understandably, this is not in any way PlayedForLaughs.
* CassandraTruth: What Jack Ryan spends most of the novel spouting. He is ignored mainly because of Liz Elliott's personal dislike for him and her undue influence on Bob Fowler. Despite being proven right time and time again, it takes him literally intervening in the HotLine to avert the ultimate crisis.
* ChekhovsGun: You didn't think he spent all that time talking about those logs for nothing, did you?
* DeathEqualsRedemption: While not exactly a villain in this case, Harry Ricks apologizes to his XO for the way he commanded ''USS Maine'' shortly before [[spoiler:they're hit by one of ''Admiral Lunin'''s torpedoes]]. Thankfully, it ends better for most of the rest of the crew.
* DefconFive: Averted. After the [[spoiler:nuclear bomb goes off in Denver]], President Fowler orders the military to DEFCON 2, and then to DEFCON 1 after the [[spoiler:attack on US troops in West Germany]].
* DefrostingTheIceQueen: Bob Fowler and Liz Elliot do this to each other, but only for each other.
* DidTheEarthMoveForYouToo: A throwaway joke made when the terrorists are digging up [[spoiler:an unexploded nuclear bomb.]]
* DisproportionateRetribution: A sizable portion of the novel consists of Elliot trying to ruin Ryan's career and marriage because he objected to her bad manners in ''Literature/ClearAndPresentDanger''. It makes more sense when you figure out that she's a petty, vindictive bitch.
* EmptyQuiver: Forms the basis of the plot, with a nuclear weapon lost during the [[UsefulNotes/ArabIsraeliConflict 1973 Arab–Israeli War]].
* {{Expy}}: Bob Fowler and Elizabeth Elliot make a good [[Literature/TheBible Ahab And Jezebel]] allegory. On his own, when he listens to competent advice and doesn't have a PoisonousFriend whispering in his ear, he's still somewhat arrogant and out of his depth, but can be a halfway decent ReasonableAuthorityFigure. Unfortunately, Elliot does her best to corrupt him into being as venal, paranoid, and selfish as she is, and his nobler qualities greatly suffer as a result.
* FalseFlagOperation: The terrorists' plan in the event of their capture is to implicate another country for the Denver bombing, to cause the expected revenge bombing by the US to cause a massive uprising [[spoiler:by the Arab world.]]
* {{Fingore}}: John Clark [[JackBauerInterrogationTechnique interrogates]] a pair of Arab terrorists and breaks their fingers to get information to help track down those responsible for their attack. The terrorists [[OutGambitted promptly finger a non-guilty party]].
* FormerRegimePersonnel: The False Flag Operation that was part of the terrorists' plans [[spoiler:to get the US and the Soviet Union fighting one another]] was assisted by several former agents of the East German [[StateSec Stasi]], who also arranged for the technical expert to work on the nuclear bomb they had acquired.
* GoodPeopleHaveGoodSex: Averted when Ryan's drinking and stress fatigue nearly destroy his sex life (and marriage).
* TheGreatPoliticsMessUp: The novel was written prior to the collapse of the Soviet Union, but set chronologically afterwards. Oops. Though Narmonov is pretty clearly written as a Gorbachev expy. It isn't so much a matter of assuming that the USSR would continue, but not being able to predict exactly how it would fall apart.
* HeroicBSOD:
** Ryan experiences a drawn-out, stress-induced breakdown - one of the few times in the series that he has not been up to the task at hand. This is due to finding himself working for a hostile administration without much in the way of support.
** [[spoiler:At the very end of the novel, after stopping Fowler from launching a nuclear strike on Iran, Ryan decides to leave government service. It isn't until ''Literature/DebtOfHonor'', years later, that he recovers.]]
** [[spoiler:DespairEventHorizon: Fowler, after discovering that he had very nearly ordered a nuclear strike on an innocent city, realizes that he has lost the moral right to govern the United States, and resigns in disgrace, leaving Roger Durling to succeed him as President.]]
* HiddenDepths: In a somewhat dark example, President Fowler muses early in the book that he doesn't have it in him to give the order to use nuclear weapons and [[TemptingFate is glad he lives in a world where this kind of action is no longer necessary.]] After the Denver attack and he learns the "truth" that Iran was behind it, his knee-jerk reaction is to order a nuclear strike on the city where the Ayatollah lives.
* HotLine: Played realistically in that instead of the stereotypical "red phone" with national leaders directly conversing, it's a teletype connection with translators on both ends. Using this form of communication [[spoiler:causes the U.S. and the Soviet Union to edge closer to nuclear war because the U.S. President, after hearing reports of a possible coup d'état in the Soviet Union, believes he's talking to someone other than the Soviet Premier.]]
* ItsForABook: While doing the research for the novel, Clancy was able to get the specifications for all the machinery needed to build a nuclear bomb delivered to his doorstep. He then pointed out in his author's notes that it's all commercially available within the U.S.[[labelnote:*]]The process for making a nuclear weapon has been public for decades. The limiting factor is the nuclear material: uranium and plutonium. This is not a failing of national security, however, but rather due to the nature of scientific discovery, which is lampshaded in the novel several times: what takes the work of the most brilliant minds of a generation is the work of a technician once the process is perfected.[[/labelnote]]
* JackBauerInterrogationTechnique: John Clark uses this; also a case of MutilationInterrogation by way of {{Fingore}}. It fails in that the badguys were planning all along to lie under interrogation to [[FalseFlagOperation falsely implicate]] Iran in their bomb plot.
* {{Jerkass}}: Harry Ricks, newly minted commander of USS ''Maine'', is a hardcase engineer with a bad case of MilesGloriosus when it comes to actual command. Elizabeth Elliot, Fowler's National Security Adviser, is worse, attempting to ruin Ryan's life on the basis of a petty vendetta and driving Fowler to the brink of nuclear war through sheer paranoia.
* JerkWithAHeartOfGold: President Fowler. He's a jerk towards Ryan from the get-go, but he's also an honest politician who despises corruption, hates child exploitation, and values his underlings. Even when he's putting Ryan out to pasture, Fowler is willing to give him a glowing send off out of respect for his meritorious service.
* LifeImitatesArt: It's mentioned that local wags near the [[UsefulNotes/PeaceThroughSuperiorFirepower Strategic Air Command]] HQ joked that the relatively new (at the time) Command Center was made so that the actual place matched up with the common Hollywood depictions of the facility, which were better than the original structure. [[invoked]]
* MistakenForCheating: A stressed-out Jack withdraws from Cathy, leading her to believe that he's having an affair. Add to that a mishap with a perfume bottle, and a news leak by vindictive bitch Elizabeth Elliot about "a senior intelligence official"...
* MyGodWhatHaveIDone: Both Fowler and Elliot go into full BSOD mode when they realize how close they came to starting WorldWarThree. [[spoiler:Fowler resigns his presidency immediately afterwards. Elliot, on the other hand, collapses into paranoic rambling and suffers a mind break, ultimately requiring hospitalization.]]
* TheNeidermeyer: Captain Harry Ricks is a combination of this and DrillSergeantNasty. He's constantly yelling at his crew for not living up to his standards, bullying them for minor infractions, and demanding perfection one hundred percent of the time. All for the goal of one day becoming the Chief of Naval Operations or Naval Reactors. His superior, far more reasonable Admiral Mancuso, realizes this and is prepared to ensure Ricks never gets beyond the rank of Captain. [[spoiler: It doesn't matter since Ricks dies when USS Maine is sunk, though not before apologizing to his XO for being an ass]]
* NotSoDifferent: It's pointed out a few times that Fowler and Ryan share many characteristics and traits, notably their honesty and integrity. However, because Fowler's main focus was on domestic issues (as opposed to Ryan being a foreign specialist), and due to him getting off on the wrong foot with both Fowler and Elliot, they end up personally butting heads throughout the whole novel.
* OhCrap: Just about everyone has this reaction when they're informed that there's been a nuclear explosion in Denver.
* OpenSecret: The White House staff and press are easily able to tell that President Fowler and Liz Elliot are sleeping together. The press reasons that so long as the personal relationship doesn't harm the professional one, they'll keep it to themselves. It comes back to bite the entire world in the ass when it does become a problem at the worst possible time.
* PointyHairedBoss: Marcus Cabot, Ryan's direct superior, is portrayed as a lazy boss who does nothing noteworthy but to cause trouble for Jack. Due to his general incompetence, Ryan is essentially the one who runs the CIA.
* PreventTheWar: The villains are attempting to provoke a war between the USA and the Russians by detonating a nuclear bomb at the Super Bowl, and by instigating another attack; in the book, East Germans disguised as Russian commanders get the Russian tanks to fire at the American tanks near Berlin, in the movie, a well-bribed Russian air force general instructs his air wing to attack a US aircraft carrier. Jack Ryan and John Clark have to find out what really happened before one side starts nuking the other.
* ReasonableAuthorityFigure:
** Played straight with President Fowler for most of the novel, but then subverted after the nuclear attack on Denver. A combination of Elliot's paranoia, his drinking, and his mistrust of the CIA in general and Ryan in particular compromises his judgment and hence his responses to the crisis.
** Vice President Durling plays this straight for the entire novel.
** Secretary of Defense Dennis Bunker is explicitly identified as one of the most reasonable members of the Fowler administration, respected by both generals and grunts. [[spoiler:Pity he dies at the Super Bowl.]]
* RetiredBadAss: Though not technically ''retired'': due to the downsizing of the CIA under Fowler, Ryan had to pull some strings to have Clark and Chavez transferred to the Domestic Protection Service as his bodyguards. They both excel in the role, but all three recognize that it's a holding pattern until they're able to get back into the Operations Directorate, possibly under a new President. [[spoiler: They do get into actual spy operations at the end of the novel, which helps them get into place to capture the terrorists when they try to escape.]]
* RichBitch: Elizabeth Elliot, made worse because of her relationship with President Fowler. She becomes his most trusted advisor but her paranoid insecurity causes her to lead him to the brink of nuclear war. She has a full on breakdown afterwards.
* ShoutOut: ''Literature/BlackSunday'' is mentioned with the terrorist attack on the Super Bowl.
* TortureIsIneffective: The terrorists who nuked the Super Bowl are captured by Clark and Chavez. Clark uses some Fingore on them to get information on their backer, and after holding out for a while, the terrorists finger the nation of Iran. The catch is that they had planned this as an attempted XanatosGambit: if the US does retaliate against Iran, they will have "made an enemy out of all Islam".
* TrustPassword: Used in a way, when Ryan gets on the text-based HotLine with the the Russian President, Andrey Ilyavich Narmonov. Ryan asks him if he still makes his own fires in the dacha, a CallBack to their in-person meeting in Russia in ''Literature/TheCardinalOfTheKremlin''. Narmonov responds by asking him questions about the incident that only Ryan would know.
* TwentyFifthAmendment: Roger Durling's final scene is him getting comfortable in the Oval Office with Arnie Van Damm addressing him as 'Mr. President'. It's heavily implied, and later confirmed in subsequent novels, that Fowler resigned from the presidency after having a mental breakdown.
* WesternTerrorists: The Warrior Society, a group of Native Americans terrorists who had gotten into dealing drugs to fund their activities.
* WillingSuspensionOfDisbelief: Lampshaded by various characters, who find it hard to do this over the sweeping political changes that drive the conflicts of the book.
* WomanScorned: Liz Elliot holds a personal grudge against Ryan from their first meeting in ''Literature/ClearAndPresentDanger'', abusing her powers to get back at him and try to destroy his marriage.
** This gets extended later to Cathy Ryan, who, after discovering that [[spoiler:the circumstantial evidence of her cheating husband was actually him keeping his promise to take care of Buck Zimmer's family]], turns around to publicly humiliate Elliot at a party.
* XanatosGambit: The terrorists' plan has multiple outcomes, all of which work to their benefit. If U.S. blames the Soviet Union for the nuke, it's WorldWarThree. If not, they've still killed a lot of people. If they get away, great; if not, they've got a FalseFlagOperation set up to implicate Iran.
* YouAreInCommandNow: Happens quite a bit as a result of the Denver attack.
** CINC-NORAD was killed in the attack leaving his two-star subordinate in charge.
** Ryan, Dan Murray, and Captain Rosselli are the most senior officers present at their respective agencies, leaving them to advise President Fowler.
** Roger Durling becomes president after Fowler has a mental breakdown and resigns.
* YouHaveOutlivedYourUsefulness:
** Subverted. The [[spoiler:nuclear]] scientist ''hadn't'' actually finished his work [[spoiler:on the bomb]] yet. Because of that, its effect is significantly lessened, and provides the vital clue that keeps the US from launching its arsenal [[spoiler:at Russia]].
** Played straight with the terrorists' U.S. accomplice, whom they murder once their device is planted.
* YourDaysAreNumbered: Qati, the leader of the terrorist group, is dying of cancer. He views their plot as his [[TheLastDance last chance]] to strike a devastating blow against America. His cancer meds are a ChekhovsGun that clue Clark into seeing through the FalseFlagOperation.