Note: this contains spoilers. This is how I imagine the producers dreamed up the story.
Interior , conference room, Dune Entertainment studios, December 2011
CEO : All right fellas, action movies are the new blockbusters. What can you make?
Flunky 1: Well, we have the movie rights to several franchises; X-Men, X-Files, Avatar, The A-Team, Die Hard–
CEO: Yes! Die Hard! I love that John McClane! He's your normal guy who winds up in the middle of trouble every time.
Writer: Right, the reluctant hero. That's what made him stand out over the other action heroes.
Flunky 2: Well sir, James Bond is also coming out next year, maybe we should look into other genres. We've been making a lot of cash off of horror flicks...
CEO: No way! We need a white American action hero. None of this James Bond British stuff, he's like 50. Audiences love seeing a young badass American hero kill dozens of bad guys. What can we do with it?
Writer: Well, I wanted to take John McClane and put him somewhere new. Push the story in a new direction. We've had him fight terrorists in a skyscraper, in an airplane, in New York City, and Washington. What can we do next?
Assistant: Have him travel outside America?
CEO: Perfect. Think of how awesome it would be. It's like Bourne Identity, only he wisecracks a lot more.
Flunky 2: OK, where would you want to put him? Iraq?
CEO: Heck no, too political and audiences don't want to hear more about that heap. Somewhere exotic and dangerous.
Flunky 1: How about Russia?
CEO: Yes! Scary armed and dangerous place. Perfect.
Writer: Well, there's been a lot of James Bond movies involving Russians.
CEO: That's why we'll outdo them! Bigger action. We'll add our own touch, how about the CIA works with him? Audiences will love it. John McClane and American spies working together.
Writer: Well that's certainly new. We could actually involve actual landmarks in Moscow, like the Kremlin, Red Square–
CEO: No, no, no. What is this, Mission: Impossible all over again? The teenagers who watch this movie aren't Tom Clancy fans. Americans don't know jack about Russia.
Flunky 1: Plus it's gonna be real expensive to film in those places.
Flunky 2: Let's set the movie in a part of Russia that everyone knows. How about Chernobyl.
Writer: That's kinda tasteless.
CEO: Screw taste! Everyone's heard of that place. Think of the buzz it will create! John McClane, fighting Russian terrorists at a radioactive Chernobyl.
Flunky 3: Yeah, I can imagine it now, battling at the nuclear plant and John McClane says his signature line, "Yippie kay-yay mother-f****r" and throws the villain right into the nuclear smokestack.
Writer: Oh come on, that is a ripoff of both X-Men: Wolverine and James Bond's For Your Eyes Only.
Flunky 3: Ok, ok, no smokestack. Maybe he gets thrown into a helicopter's rotor blades.
Flunky 2: Yeah, some epic win.
CEO: I like it. Let's make a villain that the audiences want to see get pulverized. Terrorists, obviously. Muslim ones?
Writer: Nope, for the same reason we couldn't do it for The Sum of All Fears. They'll call us all racists and bigots.
Flunky 2: All right, then let's stick with Russians again.
CEO: Now what do they want?
Flunky 1: Money. A heist movie?
Writer: Come on, the last 3 prequels were all heists. Let's try something new.
CEO: I still like my CIA idea... OK, how about John McClane helps the CIA in a mission to stop WMDs from being given to Al Qaeda?
Writer: I could write that.
Flunky 2: But it has to have plot twists.
Flunky 3: And McClane needs a personal crisis.
Writer: I was thinking of picking up where McClane's backstory wandered off. How about we bring his family back into the picture?
CEO: Yes, he needs a sidekick. How about his son?
Flunky 1: A young John McClane junior? Better look for a WWE star.
Flunky 3: Yeah, the only thing better than one McClane is two!
CEO: Perfect tagline for the movie poster.
CEO: And don't forget the hot Russian chick.
Flunky 2: Make her a spy and have her turn bad halfway through. There's our Plot Twist!
Writer: Anything else?
CEO: An epic car chase
Flunky 1: With huge explosions and car pileups.
Flunky 2: And with a big Russian tank!
Writer: You'd be ripping off Goldeneye again. James Bond?
CEO: Oh, we can outdo James Bond. That was what, 1990? We can make it better. Rather than a regular chase through the streets, let's flip trucks, drive cars off bridges, machine gun fire at speeding cars through rush hour traffic.
Flunky 3: Yeah, and CIA drones flying overhead.
Flunky 2: And parked cars exploding one after another down the street. It would be a great commercial.
Writer: Oo-kay, I'll see if I can take all your notes and come up with a script.
CEO: Have it ready by next week.