Why do most American movies that take place in foreign countries have people with other accents?

I have noticed in most American movies, with few exceptions, taking place in other countries have only characters with English or American accents regardless of the country it takes place in. For example in Gladiator most of the starring roles had English accents, as well as in 300. In Valkyrie, most of the main characters had English accents despite the fact that they were all German. The lead role, Tom Cruise, even had an American accent. Is there a reason for this?|||Because it's hard to understand someone with a strong accent, so by having an American play the role and speak English, it makes it easier to understand while still putting us in the mind-sense that it's a German or someone talking.





Also, sometimes names sell movies, such as Tom Cruise. That movie might not have done so well if a no-name real German or a lesser known American actor was playing that role, and Tom Cruise can't do a good German accent, hence, why it was American.





*edit*


Reading over your question I would just like to add another example, in 300 Gerard Butler was the star, and he is from Scotland, and it's easier for him to do a British accent than whatever accent/language the Spartans should speak.





Did you know they changed the ethnicity of the Camerlengo in Angels and Demons from Italian to Irish because Ewan McGregor couldn't do an Italian accent? That one upset me a lot, but I love Ewan so I forgave it.





It's all in the names.|||Most of those films aren't made for linguists or for language experts, and their sociological accuracy's often overlooked in favour of bringing a marketable product. And when it comes to marketable products, having big names, the odd sexual innuendo and/or chasing scene and giving an expected ending are way more important than getting the accents right.





I do find that a bit annoying, to be honest: 'Dracula' gets ruined by Mr Reeves' poor English accent... they could've changed the plot (making Jonathan an American state agent rather than an English one) or changed the actor, but they did neither. Same for Wynona Ryder... Oldman's pseudo-Romanian accent was a bit streched IMO. The film's great otherwise, but those accents ruin it.





'Saw' is an interesting case: they all speak American (on the first film) although both victims are played by non-American actors. As for the original 'Star Wars' trilogy, it's interesting and a bit too coincidental that the American blokes were the good guys and eventually won, while the evil ugly Emperor spoke Scottish, and the elder wise master spoke RP (but gets killed anyway).|||They have discovered that a poorly done accent is more of a distraction, and likely to be ridiculed. I personally think you should be able to overlook that and just enjoy being able to understand the actors.|||I think the English accent is meant to be universal for all other nations. Like in Star Wars, all the Empire had Englsih accents,