No need to apologize.... I think you should attempt to make your idea come true. Some ideas I have!!!
1. (Enemy) has had dictatorship over the island for 20 years
2. (Enemy) Army presence not severely large on island but reinforcements could be dispatched in several hours
3. Have the enemy in several cut scenes go to different towns find people and execute them or take them away to prison
4. US tired of the current (Enemy) leader dictatorship, using the CIA and Special Forces go in and train local guerillas
4. Use the Resistance soldiers and show them getting trained and stuff....
Let your mind run wild.... you don't have to be precise on the history, just have fun.
(Enemy) - Russian, Cuban, ect.