Why does the end of the world ONLY ever affect the USA in movies?

Rating: 2/10 (16 July 2008)

Can somebody please explain to me why, in almost every 'disaster' movie, when the planet is threatened with extinction, the only viewpoint shown is American, the only government depicted is that of the USA and the only cities ravaged by 'special effects' are NYC & LA? I appreciate that these are Hollywood movies, but come on!
As for the film itself, which I watched on TV last night because there was little else on, I can only concur with others here, about the clichés, the pathetic 'coincidences', the ludicrous inconsistencies and the implausible plot twists. The only thing missing was a guitar-playing Nun! While I enjoyed some of the effects work, the script was beyond redemption and seemed to be aimed at kids under 7. In fact, that is doing the under 7s a great disservice.
I am sure however that George Dubya loved it...