What communication problem existed between Captain Keller and Annie? Captain Keller and Kate? Captain Keller and James? And James and Kate?
Captain Keller's main problem in communicating with the others is that he has never quite given up being on the battlefield. He gives an order and expects it to be obeyed. He treats the others as if they were soldiers under his command.
What he fails to realize is that each of the other characters is fighting their own battle in their own way. While the battle ground may be Helen, their tactics differ radically one from the other.
Also, each is fighting with his/her own weapon: Captain Keller, power; Kate, love; Annie, education; James, cynicism. Therefore the conflict is not in the battle itself, but in the tactics and weaponry.