There’s a lengthy post on Rotten Tomatoes detailing the authors views on the symbolism of Snakes on a Plane and how the movie is going to be one large analogy to World War II:
How does Snakes on a Plane relate to this? The snakes in Snakes on a Plane are a symbol for the Japanese’s evil use of aviation to destroy Pearl Harbor. In essence, this plane in the film, will be filled with Snakes. Without the Snakes the plane is just a harmless tool, but with snakes on it becomes a dangerous weapon. So you might say the snakes represent the possibility of turning aviation into a dangerous weapon. The snakes represent that possibility, they represent the Japanese during WWII. Once the “devils” aka Snakes infest the plane, it becomes a weapon that can harm.
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Sam Jackson represents the isolationist America. In the beginning of the film he won’t be a loud mouth, he won’t make conversation with the people around him, he’ll sit in his seat like a sleeping giant. But when those snakes attack, when that Snake Pearl Harbor happens, the sleeping giant will awake. Like he says in the trailer, “That’s it, I’ve had it with these snakes.”. Clearly writing inspired by FDR’s speech on Dec. 8th.

That actually works, but isn’t Snakes on a Plane a better allegory for September 11th?