Factual error: When the presidential Boeing 747 is taking off with vice president, it is said that the plane will get to 30000ft in 45 seconds, which is the sort of climb rate only attainable by fighters, not jumbo jets, even at presidential specifications.
Audio problem: When Cale is kicking the terrorist in the bathroom he says "You think you're tough?" However his face is scrunched up and his mouth is not moving when the audio is heard. (00:38:10)
Continuity mistake: When Cale asks his ex-wife what he has done, he has the envelope he is holding in one hand in one shot and both hands in the next. (00:10:05)
Answer: Knowing is not believing. They might know, but they wouldn't necessarily trust the media. After all it could have been a grand conspiracy to cover up the actual truth from the people.
Alan Keddie
I highly doubt world war 3 would start before these countries did their homework though. It wouldn't take long for them to suss out it was actually terrorists who detonated the bombs and not America.
The_Iceman