By Thomas Mahnken and Bryan Clark
The US undersea deterrent is the most survivable leg of America’s nuclear triad of ground-, air- and sea-based nuclear capabilities. The sea-based leg, however, is also the most brittle of the three. If an alert nuclear-powered ballistic missile submarine (SSBN) is prevented from launching its missiles, is unable to communicate with commanders ashore, or is destroyed, all of its missiles become unavailable at once. If only one SSBN is on alert patrol, this could eliminate an entire leg of the triad.
