Factual error: Jack Ryan takes the enlisted oath, not the officer's oath, when commissioned into the Marines. (00:02:35)
Factual error: In the Dearborn, Michigan car chase scene, a car is shown with a Michigan front license plate. MI is one of 13 states that does not have front license places.
Factual error: In the chopper at the beginning of the movie, the soldiers have their rifles pointed upwards. When in helicopters, soldiers always point their rifles downward, so that an accidental discharge would go through the floor rather than the engine above them.
Factual error: At the beginning of the film, Jack is a student at the London School of Economics. The London School of Economics is a relatively modern urban campus in the middle of downtown London, not the fairly spacious, older campus depicted the movie.
Answer: This is true of all versions of the character - his name's officially John Patrick Ryan, but he always goes by Jack.