Strategic Nuclear Triad

Three major types of nuclear weapons systems in the strategic forces of the United States; consisting of land-based missiles, strategic bombers, and submarine-based missiles. The purpose of maintaining the triad is to create a flexible series of policy options in the event of a nuclear crisis. The various programs that make up the triad have a variety of strengths and weaknesses that account for, and are reinforced by, one another.

Land-based missiles are the most accessible from the command perspective because of the simplicity of communications and officers with access to firing circuits. They are subject to the greatest degree of control and promise great accuracy once fired. Their greatest disadvantage lies in the fact that their locations are fixed; thus they are easily targetable. More important, once launched they cannot be recalled. Thus, their use requires extremely high levels of assurance.

Unlike missiles, bombers can be recalled, and their location is not fixed, making them less vulnerable to attack. Their disadvantage relative to missiles, however, lies in the slow delivery time entailed by bomber-based nuclear weapons.

The submarine-based missiles are the safest part of the nuclear triad in terms of their relative invulnerability to a first strike. The mobility of the submarine forces, in addition to the near impossibility of hitting them all at once, makes them the most survivable. The disadvantage, however, is that it is nearly impossible to maintain two-way communications with a submarine without revealing its location. Because the location of the submarine and its relative motion at the time of launch are more difficult to determine, the missiles are less accurate.

The strategic nuclear triad has provided the foundation of U.S. nuclear strategy since the early 1960s.