What is a reason a U.S.-based lawyer would choose to get an LLM degree?

Responses

To practice law in a law firm outside the United States.
To practice law in a law firm outside the United States.

To effectively work with non-U.S. lawyers.
To effectively work with non-U.S. lawyers.

To conduct in-depth legal research into an area of law.
To conduct in-depth legal research into an area of law.

To gain subject matter expertise.
To gain subject matter expertise.