The movie opens with clips of the US military scrambling to respond to a Soviet nuclear attack. Daniel Schorr, reporting in front of the White House, is vaporized when a nuclear weapon detonates.
In the summer of 1989, East Germany is in turmoil. Many citizens are dissatisfied with their nation’s Communist leadership and seek unification with West Germany. On October 7, Mikhail Gorbachev, a supporter of those reforms, visits East Berlin. During his return flight, the hard-line Communist leadership stages a coup that deposes Gorbachev and installs (fictional) General Vladimir Soshkin as the new Soviet leader; Gorbachev's eventual fate is "lost in the darkness of history".
Soshkin and the hard-liners fiercely resist the rise of glasnost and perestroika. They are determined to end the uprisings in East Germany and the rest of the Eastern Bloc with a swift Chinese-style military crackdown in late October. (In East Germany at least, the crackdown is not limited to demonstrators; numerous moderate Communists such as Egon Krenz and Günter Schabowski are "disappeared", never to be heard from again.) The crackdown inflames popular opposition to communism. In late November, a demonstration in Leipzig is brutally repressed by the East German Army at great loss of life. Two days later, a demonstration at the Brandenburg Gate ends with East German soldiers killing many East Berlin residents trying to scale the Berlin Wall and a West German cameraman filming the events. Those soldiers also fire shots over the wall into West Berlin. Soon after, the East German government responds to the international condemnation of their conduct by ordering all foreign journalists out of the country.
In mid-December, NATO airlifts military reinforcements to West Berlin. Soon after, US Secretary of State James Baker arrives in West Berlin to secretly meet with General Dmitry Leonov, the Soviet commander in East Germany, who strongly opposes Soshkin's crackdown. However, on the way to the meeting, Leonov is killed by a car bomb, for which a West German neo-Nazi group claims responsibility. After an interview with West German TV in which Soshkin implicitly threatens West Berlin, an American colonel orders that tactical nuclear weapons in West Germany be placed on high alert. Soshkin responds with new threats, a massive deployment of the Soviet submarine fleet, and incursions of Soviet Bear bombers into Alaskan airspace.
On January 25, 1990, Eastern troops cut off transportation and supply links between West Germany and West Berlin, and the Soviet Air Force mobilizes to close off East Germany's airspace. Soshkin hopes the plan will prevent the West from entering into the Eastern sphere of influence and cut Berlin off from the West. NATO forces start a full-scale deployment into West Germany, and many citizens in West Germany are preparing shelters should the worst come.
As the United States prepares their first military convoy across the North Atlantic, the Soviets announce their intention to blockade the US Navy transports. Soshkin desires to cut off Western Europe and weaken the NATO buildup. The US and Britain condemn the blockade and declare it to be an act of hostility. On February 18, the United States Navy violates the blockade, and US ships are attacked by Soviet forces. Nearly a quarter of the convoy is lost in the ensuing battle before American and NATO forces clear the sea lanes. Shortly afterwards, the United Nations Security Council holds an emergency session in New York City in the hopes of diffusing the hostilities between the superpowers, but proves fruitless when neither side refuses to back down until other does so. War at this point seems inevitable.
The world panics after the failed session and the United States dispatches (fictional) National Security Advisor Martin Jacobs to the Soviet Union for last ditch effort talks with Soshkin. Figuring that Soshkin knows that the Soviets were losing power in Eastern Europe, Jacobs offers Soshkin an extended timetable for the Soviet withdrawal from Eastern Europe in exchange for a de-escalation of the military buildup. Soshkin refuses him utterly, and thus, World War III begins.
On March 12, Soshkin orders a full-scale amphibious landing near Kiel on the Baltic coast. The landings catch NATO off-guard, and they scramble forces northward to push back the beachhead. The next day, Warsaw Pact ground forces drive through the Fulda Gap, with orders to push to the Rhine to divide the stretched out NATO force. Meanwhile, the Soviet Air Force bombards Ramstein Air Base and other NATO bases in Germany. The goal is to cripple the NATO buildup with a swift strike and then press for a new round of diplomatic bargaining from a stronger strategic position. NATO forces, faced with superior numbers and surprise, are pushed back, though they are able to inflict significant losses on the Warsaw Pact forces. By March 17, Eastern forces have advanced 50 miles into West Germany.
While preparing to launch a tactical nuclear counter-assault, NATO authorizes a last-ditch conventional air campaign, Operation Bloody Nose, launched 24 hours before the nuclear strikes were to begin. It is an overwhelming success: the initial strikes cripple Warsaw Pact command and control posts, throwing their armies in the field into chaos, and in the ensuing air battle, NATO inflicts devastating losses on the Soviet Air Force (which had already lost 20% of the aircraft supporting the initial offensives including the Mig 21,23,25 and 29) ,gaining unchallenged control of Eastern European airspace. Combined with assistance from the Polish underground that cuts off Soviet supply lines, the tide of the war turns. With their numerical superiority negated by the Western technological superiority, the East German and Soviet armies melt under NATO airfire, and Western forces enter East Germany on March 23.
NATO forces reach and liberate West Berlin on March 27. As the Soviets withdraw to Poland, Germans begin to hope that reunification is at hand. The US leadership tries to reassure Soshkin that NATO had no intention to press their advance beyond East Germany. However, unrest erupts across the Eastern Bloc as citizens of communist nations, and ethnic minorities within the Soviet Union, press for the overthrow of their leaders. Soshkin becomes desperate as the communist bloc falls apart around him, and he becomes paranoid that NATO will exploit the situation to fight all the way to Moscow.
As a show of force, on March 31 Soshkin orders a symbolic nuclear strike above the North Sea. The United States responds by going to full nuclear alert and preparing to execute the Single Integrated Operational Plan. On April 1, a Soviet radar post suffers an equipment malfunction. Falsely believing that the USSR is under nuclear attack, Soshkin orders an all-out nuclear strike against the West. The US and NATO respond in kind. thousands of nuclear devices are launched across the Northern Hemisphere. "There is no further historical record of what happens next".
The movie rewinds to Gorbachev’s visit to East Germany. We then see the real celebrations of the fall of the Berlin Wall and the peaceful reunification of Germany: "History...took a different course.".The German version is preceded by a disclaimer clarifying that the events of the film are based on actual contingency plans of various governments (the filmmakers consulted numerous military experts on both sides, and received access to previously classified NATO and Warsaw Pact war plans), but that, "Thankfully for us all", the situations they were created for never happened.The news broadcasts which make up a significant part of the film are different: the German version, as a ZDF production, uses that network and its on-air personalities for the segments, while the English version shows various reporters working for an unnamed American network (for the opening scene, the English version shows Daniel Schorr's full report, while the German one has a ZDF report before switching to Schorr for the nuclear explosion).Similarly, in the German version, Senator Gramm's statements on the coup are replaced by those of Schleswig-Holstein Governor Björn Engholm, leader of the opposition SPD at that time.In the English version, other languages are subtitled (except for a Gorbachev speech about perestroika); in the German version, other languages are translated (except for field interviews with US Army officers once the shooting starts).The two West German characters, Gen. Frohm and Dr. Bruckner, speak in German in the ZDF version and English for TLC.The English version contains two scenes not included in the German one: an interview with two East German soldiers who escaped west during the Brandenburg Gate massacre, and a pair of "man on the street" interviews (one bellicose, delivered with the accent and demeanor of a stereotypical New Yorker, the other nervous but optimistic) in Times Square.The English version mentions West German, British, Dutch, and American soldiers meeting the initial Baltic attack; in the German version, Belgian forces take part as well.In the German version, the decisive NATO air assault is named "Operation Bloody Nose"; in English it is never given a name.The rewound montages between the missile-launch "ending" and the celebratory images of the actual events are slightly different.While the German version concludes with scenes from both the events of November 1989 and reunification (along with the "different course" line), the English narration has no such coda, and the montage is entirely from the fall of the Wall.