The 1991 C2 Symposium was cosponsored by the American Institute of Aeronautics and Astronautics, and held in conjunction with a conference on C2 decision aids. The symposium was divided into two tracks; the first dealt largely with strategic defense, decision making and C3 architectures, while the second dealt with C3 theory, modeling/experimentation , and tools. The papers deal largely with modeling, tools, and application of research efforts, but include a number of more theoretical pieces. There was an unstated focus on issues involving aviation, including a paper on C2 applications to civilian air traffic control.