High-alert nuclear weapon

High-alert nuclear weapon(s) commonly refers to a launch-ready ballistic missile(s) armed with a nuclear warhead(s) whose launch can be ordered (through the National Command Authority) and executed (via a nuclear command and control system) within 15 minutes or less. This can include any weapon system capable of delivering a nuclear warhead in this time frame.

Virtually all high-alert nuclear weapons are possessed by the U.S. and Russia. Both nations use automated command and control systems in conjunction with their early warning radar and/or satellites to facilitate the rapid launch of their land-based intercontinental ballistic missiles (ICBMs) and some submarine-launched ballistic missiles (SLBMs).^[1] Fear of a "disarming" nuclear first-strike that would destroy their command and control systems and nuclear forces led both nations to develop "launch-on-warning" capability, which requires high-alert nuclear weapons able to launch on a 30-minute (or less) tactical warning, the nominal flight time of ICBMs traveling between the U.S. and Russia.

A definition of "high-alert" requires no specific explosive power of the weapon carried by the missile or weapon system, but in general, most high-alert missiles are armed with strategic nuclear weapons with yields equal to or greater than 100 kilotons.^[2] The U.S.^[3] and Russia^[4] have for decades possessed ICBMs and SLBMs capable of being launched in only a few minutes.

The U.S. and Russia currently have a total of 900 missiles and 2581 strategic nuclear warheads on high-alert, launch-ready status. The total explosive power of these weapons is about 1185 Mt (megatons, or 1.185 billion tons of TNT equivalent explosive power).^[5]

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