Hot War

Notice
This is not a rip-off of "1983: Doomsday", it's just a more realistic version of it, however I'm not saying that "1983: Doomsday" is unrealistic in anyway, so don't mess this up, mods.

(Basically soviets destroy the nukes that the U.S.A sent and the U.S.A does too.)

Epilogue
22 days before the incident happened, a Korean Airlines flight from New York to Seoul was shot down by Soviet air forces after being too close to the Soviet Union mainland, they thought that was a spy plane, not knowing that later 269 people on-board would be killed later on.

The incident was the deadliest airliner shootdown up to that point in aviation history, although its death toll would be surpassed by the United States Navy's downing of Iran Air Flight 655 less than five years later, and again by the shootdown of Malaysia Airlines Flight 17 in July 2014.

On 26 September 1983, the nuclear early-warning system of the Soviet Union reported the launch of multiple USAF Minuteman intercontinental ballistic missiles from bases in the United States. These missile attack warnings were correctly identified as a false alarm by Stanislav Yevgrafovich Petrov, an officer of the Soviet Air Defence Forces. This decision is seen as having prevented a retaliatory nuclear attack based on erroneous data on the United States and its NATO allies, which would have probably resulted in immediate escalation of the cold-war stalemate to a full-scale nuclear war. Investigation of the satellite warning system later confirmed that the system had malfunctioned.

However let's say that Petrov focused more on the attack than the computer itself. The tension in the Cold War escalated quickly when anti-communist Ronald Reagan called the Soviet Union an "empire of evil". Had the situation taken a different turn at this crucial time, the Cold War could have been easily been turned into a Hot War.