As long as you are using them for newspaper or editorial or even for museums, you will not need a model release.
In general this is true. However, with the way US law works, even this is possibly not true. I just took a class on Legal Issues for Photographers, and this was a major topic (along with copyright).
For example, you cannot do anything that misrepresents the person. This will probably not be an issue if they and all their relatives are not in the US, but that can change.
Another issue would be if they became famous and came to the US. There would be issues using their image.
I've had no luck getting releases signed outside the US. I shoot in Mexico regularly and no-one will sign it.
Jeff Spirer Photos: http://www.spirer.com One People: http://www.onepeople.com/ Surfaces and Marks: http://www.withoutgrass.com