"Red Dawn"

In this remake of the 1984 action film, it's North Korea rather than the Soviet Union that invades a small American town. Standing in their way are The Wolverines, a band of teenaged militia fighters (including Chris Hemsworth, Josh Hutcherson, and Adrianne Palicki). The film would have been an early, pre-Thor starring role for Hemsworth, but MGM's financial woes necessitated a several year delay and the jump to a new distributor.