Nickolas Vassili, the writer and director of “The United States of China,” stepped in front of the gathered crowd to give some background on the work. This was Friday night, July 8, at the Palladium at Hale’s Brewery, the first of three nights for the play. He explained that he was inspired to write from the film “Network,” invoking the famous line from the film, “I’m mad as hell and I’m not going to take it anymore.”