One quality that a director needs to acquire in Hollywood is to understand the system and figure out how to work within the system to express one's own ideas.
I work from opposites to opposites, in a way. It's finding one thing and then doing the other from film to film. So maybe after 'I Saw the Devil,' I might do something like 'I Saw the Angel' or perhaps something warm and happy.
Overseas directors who want to work in Hollywood, the language barrier is not a problem. With the right talent, any director can be successful.