A high-alert nuclear weapon commonly refers to a launch-ready ballistic missile that is armed with a nuclear warhead whose launch can be ordered (through the

National Command Authority National Command Authority may refer to: * National Command Authority (Pakistan) * National Command Authority (United States) National Command Authority (NCA) is a term that was used by the Department of Defense of the United States of America to ...

) and executed (via a nuclear command and control system) within 15 minutes. It 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 United States 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 A submarine-launched ballistic missile (SLBM) is a ballistic missile capable of being launched from submarines. Modern variants usually deliver multiple independently targetable reentry vehicles (MIRVs), each of which carries a nuclear warhead ...

(SLBMs). Fear of a "disarming" nuclear first strike, which would destroy their command and control systems and nuclear forces, led both nations to develop "

launch-on-warning Launch on warning (LOW), or fire on warning, is a strategy of second strike, nuclear weapon retaliation that gained recognition during the Cold War between the Soviet Union and the United States. With the invention of intercontinental ballistic m ...

" capability, which requires high-alert nuclear weapons that can launch within 30 minutes of a tactical warning, the nominal flight time of ICBMs traveling between both countries. 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. The United States and Russia have for decades possessed ICBMs and SLBMs that can be launched in only a few minutes. The U.S. and Russia as of 2008 have a total of 900 missiles and 2581 strategic nuclear warheads on high-alert launch-ready status. The total explosive power of the weapons is about 1185 megatons, or the equivalent explosive power of 1.185 billion tons of TNT.Starr, Steven. "High-alert nuclear weapons: examining the risks." SGR Newsletter, No. 26, Autumn 2008, in press.

Notes and references

{{DEFAULTSORT:High-Alert Nuclear Weapon Nuclear weapons Nuclear warfare