Over the past decade, both official defence establishments and independent strategic analysts have devoted increasing attention to the command, control, communications and intelligence (C3I) systems which support the US and Soviet strategic nuclear forces, and to the role of these systems in crises and in strategic nuclear war-fighting. In particular, specific consideration has been given to such critical issues as the extent to which current strategic C3I systems enhance crisis stability or instability, and whether or not they would serve to control escalation in the event of a strategic nuclear exchange or, because of their vulnerabilities, would in fact contribute to the dynamics of the escalation process.