The nuclear triad is a military concept and force structure that ensures a nation can deliver nuclear weapons from three distinct platforms: land, sea, and air. This structure was a central element of U.S. military strategy during the Cold War, with the U.S. strategic arsenal adopting the system in the 1960s. The triad was created to solve the problem of a potential enemy destroying a nation's entire nuclear force in a first-strike attack. By diversifying the arsenal, it preserves the ability to launch a devastating second strike, thereby increasing nuclear deterrence and leading to the concept of Mutually Assured Destruction (MAD).
The mechanism works through the complementary strengths of its three "legs":
- Land-based intercontinental ballistic missiles (ICBMs) provide rapid response and are highly accurate.
- Sea-based submarine-launched ballistic missiles (SLBMs), deployed on ballistic missile submarines (SSBNs), offer the highest survivability because they are difficult to track, guaranteeing a retaliatory strike.
- Air-based strategic bombers are flexible, can be recalled if a crisis de-escalates, and can be dispersed quickly to enhance their survivability.
The triad is fundamentally connected to the broader concepts of nuclear deterrence and second-strike capability. For India, the concept connects to the Nuclear Command Authority (NCA), created in 2003, and the Strategic Forces Command. India achieved its fully operational nuclear triad in 2018 with the deployment of the SSBN INS Arihant. Recently, the U.S. has planned a major modernization, including replacing the Minuteman III ICBMs with the LGM-35A Sentinel and the Ohio-class SSBNs with Columbia-class boats.