Executive Meddling: For the remake, the enemies were changed from Chinese to North Koreans in post production, mostly to help the film secure a distributor, as no other major studio wanted to touch a film about China invading America. This happened after production ended, so they had to digitally alter all Chinese symbols and dub all Chinese dialogue.
The Shelf of Movie Languishment: Actually managed to make it all the way through the production phase, only to get sunk by MGM's financial insolvency. It was also delayed because the premise of China attacking America scared off all other major distributors, so MGM had to change the villain to North Korea in order to make it more attractive to film companies, and even then it took several months before it finally found a distributor willing to take a chance on the film. It probably helped that Chris Hemsworth and Josh Hutcherson had recently found fame for Thor and The Hunger Games, respectively.