They are revealed to be an anti-capitalist terrorist organization, which steals three nuclear weapons from the U.S. Air Force during the novel and plans to use them to wipe out the upcoming North–South Summit in Cancun, hosting all the major world leaders outside of the Eastern Bloc and China.
The two plot lines are joined at the end of the novel, when the terrorists - having hired Lady X, the heroes' nemesis - succeed in stealing two of the three F-14s in Managua, which they intend to use as a delivery system for the bombs (the F-14 being the plane best capable of penetrating the security screens that will surround the conference).
CIA is skeptical, but Admiral Walker allows Danny and Tuckson nine days of shore leave, during which they rent a private aircraft and systematically overfly the deserted islands in the Caribbean where the terrorists may have hidden the Tomcats.
The novel opens with Danny and Tuckson being rescued from the cay by a Cuban fr:Classe SO-1 corvette (patrol boat), which, made suspicious by the presence of American aviators in the area, takes them both prisoner.
Reagan, once informed of the crisis, arranges for the media to delay news of his arrival by one hour; this allows the Kennedy to evacuate the leaders from Cancun, and to position its fighters to intercept the terrorist planes.
When the IFARG, hiding in the Exuma islands, receive the delayed news of the President's arrival in Cancun, they launch the final phase of Operation Apocalypse, and release their F-14s carrying one nuclear bomb apiece.
First among these is the rise of international terrorism; the fictional group IFARG was inspired by the real-life Provisional Irish Republican Army, Baader Meinhoff Gang, and Islamic Jihad Organization.