Milius, who directed and co-wrote the original, is not part of MGM's planned revamp - and he can't believe it's going ahead.
He tells the Los Angeles Times newspaper, "I think it's a stupid thing to do. The movie is not very old."
And Milius insists the new script is "terrible".
He adds, "It's all about neat action scenes and has nothing to do with story."
The original featured future Dirty Dancing stars Patrick Swayze and Jennifer Grey and Emilio Estevez; the remake will star Chris Hemsworth and Watchmen star Jeffrey Dean Morgan.
And while 1985's Red Dawn dealt with the Cold War threat that existed between the U.S. and Russia, the new film deals with plans for China to invade America - a plotline that baffles Milius.
He explains, "Why would China want us? They sell us stuff. We're a market. I would have done it about Mexico."