- This is a common title. For other uses see, The Sum of All Fears (Disambig)
1973, during the Yom Kippur War; at its height the Israelis opt for a tactical nuclear strike, but this was changed at the last minute. Unfortunately, one Mark 12 nuclear weapon was not yet removed from an Israeli attack aircraft—piloted by Motti Zadin. That aircraft was shot down and crashed into mountains in Syria, and the nuclear weapon was lost (an empty quiver).
1991, after the Palestinians start using non-violent protesting and one of the unarmed protesters was killed by Israeli police official Benny Zadin, the brother of Motti Zadin. The U.S. finds that they can no longer support Israel at the UN or politically versus the Arab nations. But the U.S. also cannot leave Israel without this support since it would risk destabilizing the region. A clever plan to accelerate the peace process was put into action, based on Jack Ryan's contacts with the Vatican and with support from the Soviet Union and Saudi Arabia, and to everyone's surprise it seemed to work. However, the venal National Security Advisor, Dr. Elizabeth Elliott hated Ryan and made sure he did not get credit for crafting the "Vatican Treaty"; the fact that she had begun a romance with the widowed President Robert Fowler made this more achievable. She later launched a smear campaign that made it seem like Ryan was having an affair with a woman whose husband died (in Clear and Present Danger) and almost cost him his marriage before John Clark and Domingo Chavez revealed the truth to Ryan's wife. Ryan was later told he had to resign, but not before he put together a covert operation involving the uncovering of a deal between corrupt Japanese and Mexican officials (giving backstory to the next book Debt of Honor).
A small group of Muslim extremist terrorists from the Popular Front for the Liberation of Palestine were not pleased though. With a lasting peace looming around the corner and the state of Israel still in existence, they were looking at a failure in their campaign. Their anger was directed towards the U.S. which had supported Israel throughout the years and now is instrumental in creating a lasting peace that made it impossible to eradicate the Jewish state.
When the terrorists come across the lost Israeli bomb, they manage to recover it and construct their own version using the plutonium as fissile material. They also enlisted the help of a disenfranchised East German physicist named Manfred Fromm. Fromm, an expert on nuclear technology, agreed to help the terrorists because their plan was designed to exact revenge on those responsible for the downfall of East Germany and the unification of his country into a capitalist, democratic state. With Fromm's expertise, the group was able to enhance the weapon and turn it into a thermonuclear device. The terrorists decided to use the weapon at the Super Bowl in Denver, Colorado, while also planning a false flag attack on U.S. forces in Berlin by East Germans disguised as Soviet soldiers. The goal of the terrorists was to start a nuclear war between the U.S. and the Soviet Union. This would accomplish two things. First, it would eliminate the American's ability to support Israel, and second, it would eliminate those two nations as the superpowers, thus punishing them for bringing an end to the Cold War and betraying World Socialism, which is a driving motivator for the East Germans, who are led by a bitter Red Army Faction terrorist named Günther Bock.
The device however did not detonate fully or properly, based on an assembly error, creating therefore only a partial atomic explosion, or fizzle. Nevertheless, the Secretary of Defense and the Secretary of State were both killed, as well as the thousands of fans in attendance and hundreds more residents of Colorado due to the primary and secondary effects of the initial detonation. Through a series of coincidences, misunderstandings and the attack on American forces in Berlin, the plan was almost a success and for a brief moment the U.S. assumed DEFCON-1 as both President Fowler and NSA (National Security Adviser) Dr. Elizabeth Elliott had lost control and were ready to begin a nuclear war. The crisis was averted when Jack Ryan, after receiving evidence that the bomb originates from the U.S., gained access to the Hot Line and managed to defuse the situation by communicating directly with the Soviet president and helped to engineer a stand-down in Berlin and cancellation of the pre-nuclear launch sequences in both countries.
A curious twist was that the terrorists devised a backup plan in the event of failure. When this happened and they were captured, they put it to work by implicating the Iranian Ayatollah Mahmoud Hajj Daryaei as responsible for the attack. The American President, Bob Fowler, was enraged, and because the Ayatollah was known to reside in the holy city of Qom, ordered the city destroyed through a nuclear attack. After Ryan averts the attack by enforcing the two-man rule, the terrorists accidentally revealed the ruse and that they devised it in order to discredit and shame the U.S. in the eyes of the world. This would destroy the delicate peace process, allowing the campaign against Israel to continue. The plan can be seen as employing the commonly used terrorist tactic called agent provocateur, the inciting agent.
The terrorists then were executed by beheading in Riyadh, Saudi Arabia, and Ryan was presented an ancient sword held by the Saudi royal family. The sword was meant to honor all who died, but it also served to remind Ryan of all who didn't die because of his actions. It was later revealed in the sequels that the gift inspired Jack Ryan's Secret Service codename "Swordsman".
- Scott Adler - Deputy Secretary of State.
- Francisco Alcalde - Father General of the Society of Jesus.
- Charles Alden - The President's National Security Adviser. Accused in a scandal and died in his office leaving Elizabeth Elliot in his place as National Security Adviser.
- William Ames - An associate of John Russell killed along with Russel in their stand off with the FBI.
- Abraham "Avi" Ben Jakob - Assistant Director of the Israeli foreign-intelligence agency, Mossad. He is Jack Ryan's Israeli counterpart.
- Dennis Black - Squad supervisor of the FBI Hostage Rescue Team responsible for stopping John Russell. Paulson and Leary are members of his team.
- Günther Bock - Former member of the German Baader-Meinhof Gang and the Red Army Faction (RAF), Bock flees Europe after his wife is imprisoned.
- G. Dennis Bunker - Secretary of Defense. Former Air Force fighter pilot and CEO of Aerospace, Inc. He currently owns the San Diego Chargers football team.
- Marcus Cabot - CIA Director of Central Intelligence (DCI). Ryan's immediate boss.
- John Clark - CIA Security and Protective Officer. Formerly a CIA instructor and Operations officer, he moved to Security due to agency downsizing.
- Nancy Cummings - Jack Ryan's secretary.
- Helen D'Agustino - Secret Service agent on the protection detail to the President.
- Elizabeth "E.E." Elliot - Special Assistant to the President for National Security Affairs, Assistant National Security Adviser. She works for Charles Alden and becomes the National Security Adviser after his death.
- Robert Fowler - President of the United States.
- Sergey Nikolayevich Golovko - Former Soviet KGB, now Russian First Deputy Chairman of the Committee for State Security.
- Walter Hoskins - FBI Special Agent in Charge (SAC) of a small FBI field office near the Canadian border, promoted to Assistant SAC Denver in charge of corruption cases.
- Hashimi Moussa - Arab college student and leader of a non-violent protest, killed by Israeli police captain Benny Zadin, starting an international incident.
- Dan Murray - FBI deputy assistant director and Bill Shaw's personal problem solver.
- Andrey Narmonov -
- Timothy "Father Tim" Riley - Jesuit priest and history teacher at Georgetown University.
- John Russell - Member of the Warrior Society of the Sioux Nation. Killed by FBI SWAT Team in an attempt to run drugs into Canada.
- Marvin Russell - John Russell's brother.
- Jack Ryan - CIA Deputy Director of Central Intelligence (DDCI).
- Kathy Ryan - Jack Ryan's wife.
- Hermann Schorner - Young Jesuit priest and assistant to Francisco Alcalde.
- Bill Shaw - FBI
- Brent Talbot - Secretary of State. Former professor of Political Science.
- Arnold "Arnie" van Damm - The President's Chief of Staff.
- Benjamin "Benny" Zadin - Youngest Captain in the Israeli National police, he defies orders and assists a group of conservative rabbis in reclaiming Solomon's Temple. He is also a brother of Motti Zadin who died in 1973.
- Mordecai "Motti" Zadin - Lieutenant in the Israeli Air Force in 1973. He piloted an A-4 Skyhawk strike fighter that crashes behind enemy lines in Syria, leaving behind an undetonated nuclear bomb that sits buried in a farmer's field for decades.
- Carol Zimmer - Widow of [[Buck Zimmer] who was killed in Clear and Present Danger.
- This book was released just days before the Moscow uprising in 1991, which finally signaled the dissolution of the Soviet Union. Russian politics in the aftermath of the destruction of the Berlin Wall is a main element of the book.