A Japanese businessman on his first visit to the United States was pleased to be invited to a U.S.

executive’s home for cocktails. He arrived promptly at 7 p.m. The host introduced him to a small group of people, and then returned to the front door to greet others who were arriving. The Japanese businessman seemed to have nothing to contribute on the seemingly mindless topics that were discussed. After a few minutes, the others in the group wandered off to join other groups, and he was left alone. Because the host did not return to introduce him to others at the party, he left and returned to his hotel. What, if any, rules of proper etiquette were breached?