The Mexican Rebellion was a continuation of sorts of the Mexican Civil War. Juan de la Barrera and his rebels continued the conflict started by General Ontiveros. The rebels acquired nuclear warheads, and stole Pakistan missiles from the Panama Canal.
Captain Scott Mitchell and the Ghosts were deployed to stop the conflict with Loyalists led by Colonel Jimenez. Eventually, Mitchell went to Ciudad Juárez and guided an EMP bomb into the last warhead. He was seriously wounded in the detonation, although survived to continue leading the Ghosts.
One of the differences between the PC and the Xbox 360 version is that the Xbox version starts with a simulaor, while the PC version starts with the Ghosts already in-country.
PFC Provenanzo only appears in the Xbox version.