In many mission critical applications current technology is inadequate for fully automatic planning and control. In these applications society insists that planning and control be exercised by human minds. However, many such applications lie at the brittle edge of human capabilities. This has lead to serious incidents such as those involving the USS Stark and the USS Vincennes in the Persian Gulf. In domains like these where full automation is unacceptable and purely human operation is inadequate, a promising approach is one which combines the strengths of humans and computers.