Hugh Marlowe movies
An alien lands in Washington, D.C. and tells the people of Earth that they must live peacefully or be destroyed as a danger to other planets.
A tough-as-nails general (Gregory Peck as General Savage) takes over a B-17 bomber unit suffering from low morale and whips them into fighting shape.
Extraterrestrials traveling in high-tech flying saucers contact a scientist as part of a plan to enslave the inhabitants of Earth.