What was the official stance of the League of Nations towards Japan's Second Invasion of China and what were the reasons behind that stance?

I am asking this because I am reading a memoir of a person who witnessed the Second Sino Japanese War. He is basically portraying the League as being a useless institution whose main goal was appeasement of aggressive powers.<br><br>Edit: Since apparently I have to spell things out for people, the first invasion was in 1931.