I'd have a foreign country making the mistake, stemming from something like poor coding and/or myopic safeguards allowing A.I. to take over their defenses and then those of the U.S. and Russia. Sounds more realistic to me.
Oh-oh. Just found this on Wikipedia:
Remake
Imagine Entertainment and Universal Studios confirmed that a remake titled Colossus, to be directed by Ron Howard, would be in production as of April 2007. Officials were quoted as saying: "Universal and Imagine Entertainment will remake the 1970 science fiction saga Colossus: The Forbin Project as a potential directing vehicle for Ron Howard, reports Variety. Brian Grazer will produce. Jason Rothenberg has been set to write the screenplay for a movie to be called Colossus. Based on a book by D.F. Jones, the original film was a forerunner of movies like Terminator, introducing the idea of a government-built computer that becomes sentient and then takes control."
In October 2010, the project moved forward with the announcement that Will Smith would star in the lead role, with the script being written by James Rothenberg. "Will Smith is set to collaborate with director Ron Howard on the forthcoming sci-fi feature The Forbin Project. But now it looks like the project might be back on track as Varietys reporting that Universal has hired writer Blake Masters (Law & Order: LA) to do a new draft of the script. Theres no word if Ron Howard is still on the project, but its possible since it will be produced by Howards business partner Brian Grazer".
Variety also reported in July 2011 that Universal replaced Rothenberg with Blake Masters to do a new draft of the script. In March 2013, it was announced that Ed Solomon, screenwriter of Men in Black and Bill & Ted's Excellent Adventure had been brought on board to rewrite the film's script. "After struggling in developmental limbo since 2007, Colossus the remake of the 1970s science fiction thriller 'Colossus: The Forbin Project' starring Will Smith has been given a much-needed boost. Ed Solomon ... has been brought on board to rewrite the films script and breathe new life into the project". No further details emerged regarding the remake.
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Please, NOT WILL SMITH. He. Can't. Act. The team of Ron Howard/Brian Grazer is totally wrong too. As is Ed Solomon.
A.I. taking over is too real and too terrifying and needs to scare the crap out of everybody. A.I. in fascist form. That type of thinking.