Triad

A three-sided military-force structure consisting of land-launched nuclear missiles, nuclear missile submarines, and strategic aircraft with nuclear bombs and missiles. The triad was a central element in the U.S. military strategy during the Cold War. The theory underlying the triad was that by having its nuclear assets spread across various weapons platforms, the force was more likely to survive an attack by the Soviet Union and be able to respond to a first strike successfully.

Following the end of World War II, the United States and the Soviet Union entered into the Cold War, a period of increased political, economic, and military tensions. Both sides engaged in a military rivalry, in which initially, the United States sought to balance its nuclear supremacy against the conventional superiority of Soviet troop strength. Later, the Soviet Union acquired nuclear technology—atomic and then thermonuclear weapons. An arms race ensued, and both sides eventually possessed extensive arsenals of nuclear missiles, bombs, and rockets.

The development of political and military strategy in that era included each nation's concern with surviving a first strike by the other. In order to ensure that sufficient nuclear forces survived to conduct a second strike, both the United States and, to a lesser degree, the Soviet Union spread their resources across various weapons platforms. These platforms included rocket-launched nuclear missiles, submarine-launched nuclear missiles, and strategic aircraft with nuclear bombs or nuclear missiles.

For example, the land component of the triad included intercontinental ballistic missiles ranging from the Atlas to Titan to Minuteman, and later, the Peacemaker missile; all were multistage rockets capable of carrying one or more nuclear weapons and guided by highly developed inertial guidance systems. With a range of 8,000 km, these missiles posed a formidable threat to an enemy. The sea component of the triad included older nuclear submarines, as well as more modern Trident submarines carrying sea-launched missiles such as Poseidon C-3s and Trident C-4s. The air component of the triad included bombers such as the old, but still flying, B-52s and newer B-1B bombers, equipped with eight or more nuclear bombs.

The triad still exists as a component of U.S. military strategy, but with reduced nuclear arsenals and inventories. Recent decisions to develop the so-called Star Wars technology, and later a National Missile Defense, will undoubtedly affect the continued reliance on the Triad.