WMG / Miracle Mile

The movie is a nightmare he is having while napping to meet Julie.

It’s a great movie, but the only plausible explanation is Harry is having a crazy dream. First, the crazy night starts with him falling asleep. And at the deli, Landa believing Harry because it matches what a RAND dude boyfriend of hers said... that’s rather implausible.

And like so many nightmares, Harry really needs to get somewhere and yet can’t seem to even leave. And there’s the completely surreal bit where Harry is trucking Julie across Park La Brea in a shopping cart.

But the main indication is that the amount of things that occur within an hour simply could not have happened, no matter how well Landa is connected. If it were two hours, I could start to buy it. Also, Wilson’s separate story of picking up his sister, getting into a fight with the cops, crashing into the store and the cops deploying a SWAT team couldn’t possibly have occurred in the ~30 minutes he had.

• The troper who posted this is unaware that this interpretation was what the producers of the Twilight Zone movie wanted for the film when they purchased the script with the intention of making it as the TZ movie, with Harry waking up after the bomb goes off and then starting to live through the beginning of the night in the same way. But, De Jarnatt refused to have the ending of the film like that, and had always intended for the film to be presented as is: that it's really happening and not a dream.

This movie is a prequel to Cherry 2000.

...

Harry has unintentionally triggered the third world war

It is possible that the phone call was just a joke. So basically, Harry started a rumour by mistake. The rumour then spread like wildfire, until it reached the ears of a Soviet informant, who immediately called their superiors in Moscow.

Of course, the Kremlin would not have launched their nukes because of an unsubstantiated rumour. But they would have immediately checked the information through other channels (secret agents, diplomats, etc...) The problem is that, as I said, the rumour has spread like wildfire, and the other Soviet informants have also heard about it - and some may also know that several politicians have left Washington. For the Kremlin, this validates the information (Like in "Puss in Boots", everybody has heard about the Marquis of Carabas, thus the Marquis of Carabas must be real.) They start to panic, and order precipitately an attack against the USA.

More generally, that fits the basic idea of the film: because of a phone call that may be nothing more than a prank, people start to panic, and things quickly get out of control. It's not far-fetched to think that the news reached more and more people, then journalists, politicians, soviet spies... and everybody panicked and believed WW3 had started, which lead to the start a real nuclear war. That also fits the genre of the movie, as in many cold war stories (Dr Strangelove, Wargames...), WW3 is triggered because of some stupid mistake.

• The only thing that counteracts this theory is the fact that Chip, the guy who called the phone, told Harry he got the area code wrong when trying to reach his father. Harry, after the cops take off, takes Julie back to Johnnie's, where he dials the number with the correct area code. Harry asks Chip's father about where Chip is, and when Harry mentions "in a missile silo", Chip's father gets irritated and says, "Hey, that's classified information!" before he hangs up. That scene is meant to establish that it wasn't a crank caller.