Originally Posted by JimHull
I guess my problem would be that if the goal of the story was Rick getting Ilsa than who would the Antagonist be? You could say Lazlo, but by definition, an Antagonist actively prevents the Protagonist from acheiving his goal. I don't see that happening.
An antagonist does not have to be a person. It can be a force of nature or a set of circumstances, although personally speaking it is usually more emotionally satisfying when the obstacle that the protagonist has to prevail over is a person.
For example, consider the threat posed to the characters in the Final Destination series of movies.
Disaster movies also provide good examples of non human antagonists. The antagonist in Deep Impact was a giant space rock. In The Happening, it was the wind. Or trees. Or something.
Okay, forget about The Happening. The point is, there are a bucketful of movies with a non human antagonist.
With regards to what prevents Rick from getting Ilsa in the end, I would say the answer is Rick's love for her.
If he'd said the word, she was there for the taking, but his love for her stopped him from asking her to throw away a relationship with a man that Rick has built a grudging respect for in exchange for an uncertain and dangerous future with him. More than anything, Rick's goal is the protection of Ilsa.