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.
In Korea, the director is on top, and the power flows down vertically. On the set, I love to come up with ideas on the spot. But in Hollywood, if I were to come up with a certain idea on set, the idea had to be taken to all these different people who had to agree.
In Korea, the director has the final word. If the director makes a decision, that decision is final. In Hollywood, every decision needs to go through the producer, the studio, and sometimes even the main actor. There is a certain procedure that needs to be followed.
Overseas directors who want to work in Hollywood, the language barrier is not a problem. With the right talent, any director can be successful.